What is low vision?

Low vision is the term used to refer to a visual impairment that is not correctable through surgery, pharmaceuticals, glasses or contact lenses. It is often characterized by partial sight, such as blurred vision, blind spots or tunnel vision. Low vision can impact people of all ages, but is primarily associated with older adults.

What is low vision care?

Low vision care, also known as vision rehabilitation, is a service provided by an eye care or vision rehabilitation professional that helps maximize the remaining vision of someone who has a vision impairment. Low vision care typically involves an evaluation by the professional and the use of low vision devices (also called low vision aids), rehabilitation training and other techniques.

How can low vision care help a visually impaired person?

Low vision care can help make the most of the remaining vision that a visually impaired person has in order to gain back independence and increase quality of life. With the low vision devices and the training provided by eye care and vision rehabilitation professionals, many people with a vision impairment can continue to read, take care of their own finances, view photographs and watch television―all on their own!

What kind of visual impairments are low vision products for?

The major eye diseases and conditions for which low vision devices are used are age-related macular degeneration, diabetic retinopathy, glaucoma, cataracts, retinitis pigmentosa, albinism, Stargardt’s disease and retinopathy of prematurity, among others.

Unfortunately, there is no one specific device that is ideal for any particular eye disease or condition?

The device needed depends on a number of variables and varies even among people with same eye disease, which is why a low vision patient should be evaluated by a low vision specialist who can demonstrate different devices to determine which one(s) work best for that individual’s needs.

Why are there so many different types of low vision devices?

Low vision devices vary for the same reason a carpenter carries so many different tools: each is good for a different task. Depending on the job, a carpenter may use a hammer, a wrench or a screwdriver. Likewise, a visually impaired patient may use a magnifier to read a pill bottle, a telescope to watch television, and a video magnifier to read a book. Each low vision device has its own set of tasks for which it is ideal and many people often use multiple devices.

How do low vision devices help those with vision impairments?

Low vision devices make the image of an object appear larger and easier to see on the back of the eye in order to better focus on the image. The magnification that is provided by low vision devices allows the vision impaired individual to be able to see around the scotomas (dark spots) that are associated with low vision. The devices improve the contrast of the object so it can be more easily separated from its background.

What are CCTVs? How do they help?

Closed-circuit televisions (CCTVs) are now more commonly referred to as video magnifiers or electronic magnifiers and come in a variety of designs. The classic desktop magnifier can be compared to a microfiche machine often seen in a public library; an object (the film) rests under a camera and an enlarged image of it appears on a monitor above. Video magnifiers act similarly to other low vision devices in that they enlarge the image of an object so that it is easier to see.

What are spectacle microscopes? How do they help?

A spectacle microscope is a pair of glasses that has a high-powered lens on one side and a clear lens on the other side. The glasses have to be used monocularly (one eye at a time) because of convergence issues. Spectacle microscopes are typically used for reading or other near tasks because in order to work properly, the object must be held very near to the eye.

What are tints? How do they help?

Contrast-enhancing glasses, filters, tinted filters, absorptive filters, anti-glare glasses or glare control eyewear―block a certain range of light and are available in a variety of tints, the most popular being yellow, amber, orange, plum and gray. The glasses are usually designed to fit over prescription eyewear and improve the viewer’s visual contrast making it easier to see an object against its background.

What are bioptic telescopes? How do they help?

Bioptic telescopes (also called bioptics) are small telescopes attached to a pair of glasses. They come in a variety of designs (attached to the top of a pair of glasses, drilled into the lens itself, etc.). When a user looks through the telescope at a distant object, the image is enlarged making it easier to see.

How can I purchase a low vision device?

Low vision products are available only through eye care or vision rehabilitation professionals (usually called low vision professionals) who are trained in being able to determine which device is best for an end user and can then fit the device and provide training to ensure success with the product. All kind of low vision devices are available at our low vision clinic. Our low vision team will help you to select the devices according to your condition and needs.

How much do low vision devices cost?

The cost varies widely by the type of product and the brand

Causes of Low Vision

Some of the most common visual impairments that can cause low vision include the following

Age-Related Macular Degeneration (AMD/ARMD)

AMD is a leading cause of vision loss among Americans over age 60. It accounts for nearly half of all low vision cases. It is caused when the part of the eye responsible for sharp, straight-on vision – the macula – breaks down and causes a loss of central vision. There are two types of AMD, wet and dry. Wet AMD is caused by the growth of abnormal blood vessels under the macula. Central vision loss occurs rapidly with wet AMD. In dry AMD, light-sensitive cells in the macula slowly break down, leading to a gradual loss of central vision.

Diabetic Retinopathy

According to the National Eye Institute, more than 30 percent of Americans diagnosed with diabetes have some form of diabetic retinopathy. It is a major cause of blindness and is directly related to high blood sugar, which damages blood vessels. That damage affects the retina and can even lead to its detachment.


Glaucoma is the second leading cause of blindness. With glaucoma, portions of vision are lost over time, usually with no warning signs or symptoms prior to vision deterioration. For many, a decrease in peripheral vision is the first sign of glaucoma.


Over 20 million people in the US alone have cataracts according to Prevent Blindness America. It appears as a clouding of the lens of the eye. Retinitis Pigmentosa: This is a group of inherited diseases affecting the retina resulting in progressive vision loss. This type of vision impairment often begins in childhood with poor night vision and progresses over time.

There are also many additional causes of low vision, including strokes, TBI (traumatic brain injury) and other diseases common among a wider age range such as Stargardts, albinism, ROP (retinopathy of prematurity), among others.

What is vision therapy(VT) ?

Vision therapy is the physical therapy given to patient who is diagnosed to have binocular anomalies

The goal of vision therapy is to optimize the visual system, and areas of the brain that control vision, visual efficiency, visual perception and other vision-related functions.

By treating the entire visual system, vision therapy aims to change reflexive (automatic) behaviours to produce a lasting cure. Vision therapy can treat vision problems that interfere with efficient reading among schoolchildren. It provides treatment for amblyopia (lazy eye), learning related vision problems, traumatic/acquired brain injuries.

It also can help reduce eyestrain and other symptoms of computer vision syndrome experienced by many children and adults that cannot be treated successfully with eyeglasses, contact lenses and/or surgery alone, and help people achieve clear, comfortable binocular vision.

Who need vision therapy?

Once you are diagnosed to have any kind of eye muscle problem after thorough orthoptics evaluation by our BVC team who will require vision therapy.

People with symptoms such as headache ,eyestrain,blurredvision,difficulty in focusing, double vision,eye pain associated with near work and computer usage .

Children with amblyopia may require special amblyopia (anti suppression )therapy .

What are the types of therapy given in BVC?

Manual exercise through synaptophore

Computerized software therapy

Take home software therapy

Take home manual vision therapy

Can these exercise improve my child vision or get rid of glasses in future ?

Probably No,vision therapy aims to provide better eye muscle coordination , can indirectly reduces the progression of power in some cases and helps to relieve eye symptoms such as headache ,eye strain,eye pain,double vision etc.

In some case some amount of squint can be controlled and corrected with these therapy .

How effective is VT?

VT is proven to be more effective in both symptomatic and asymptomatic patients who followed proper instruction and good compliance with exercise.

Will this computer therapy affect my eyes?

No ,these software therapy are designed in such a way they don’t have any adverse effect on your eyes .a pair of special glasses are provided while doing computer VT. following professional instruction helps you to achieve better result.

Vision therapy is only for children?

Vision therapy can be advised to all age group patient with binocular anomalies and vision symptoms.

What is home and in office Vision therapy ?

In office VT are exercise done in hospital under supervision of professionals.it can be both computer and manual exercise.

Home VT are exercise advisedfor patient to do in home after completing in office therapy .it helps to maintain the improvement and stabilize the condition.

How long it takes to complete vision therapy ?

It depends on the severity of the condition. Usually totally 10 sittings are advised .it can be done one hour every day or alternating days or two hours per day for 5 days ..after the completion of VT , review is done on final day to check for the improvement depending on the result your professional will advise home VT.

How often should I come for follow up?

It depends on your condition .it can once in every 3-6 months .

What if I cannot come for inoffice VT ?

There are software VT available which you can install in your computer and do VT from your home and your performance will be monitored by our team.Contact our BVC team for further information.

What is Refractive Error?

Normally, the rays of light entering the eye are brought to a precise focus on the retina – the light sensitive layer lining the back of the eye. When such a focus is not achieved, a refractive error results and vision is not clear. These imperfections in the focusing power of the eye are called refractive errors.

The common refractive errors are

1. Myopia or Near sightedness

2. Hyperopia or Far sightedness

3. Astigmatism

Myopia (Near Sightedness)

A Myopic eye is longer than normal or has a cornea that is too steep, as a result of which the light rays focus in front of the retina. Close objects look clear, but distant objects appear blurred.

Hyperopia (Farsightedness)

Hyperopia is a term used to describe the condition of farsightedness. The causes of hyperopia are typically genetic and involve an eye that is too short or a cornea that is too flat, as a result of which images focus at a point behind the Retina. People with hyperopia can usually see distant objects well, but have trouble focussing on nearby objects

Astigmatism ( Distorted Vision)

ASTIGMATISM (cylindrical error) occurs when the incoming light rays are unable to reach a common focus within the eye. Astigmatism distorts or blurs vision for both near and far objects. The cornea is the clear front window of the eye. A normal cornea is round and smooth, like a basketball. When you have astigmatism, the cornea curves more in one direction than in the other, like a football. It is possible to have astigmatism in combination with myopia or hyperopia.

Why has my child been prescribed glasses?

Learning that your child needs glasses can be an emotional experience. Some parents feel sad that their child’s eyesight is not perfect. Despite newer and more fashionable frames, glasses can seem like an intrusion on your little one's face. The key is to develop a positive attitude.

Help your child realize that the glasses will make an important difference in their eyesight. Your child will now have a chance to see better and get information more efficiently.

Parents who honestly believe that glasses are important for their child will have an advantage when it comes to getting the youngster to wear them.

Children may need glasses for several reasons – some of which are different than for adults

A child may need glasses to: • Provide better vision; to function better in his/her environment

Help straighten the eyes when they are crossed or misaligned (strabismus).

Help strengthen the vision of a weak eye (amblyopia or “lazy eye”). This may occur when there is a difference in prescription between the two eyes (anisometropia). For example, one eye may be normal, while the other eye may have a significant need for glasses.

Provide protection for one eye if the other eye has poor vision.

How important is it for children to wear their glasses?

Early childhood is the most critical period of vision development.

Blurred vision in one or both eyes can prevent the visual system from developing properly.

Wearing glasses and seeing better is proven to improve school performance. That’s why it’s important for children wear their prescribed glasses.

What are some tips for getting children to wear their glasses?

This is a question most parents ask, especially when their child is an infant or toddler. The best answer is that most young children who really need glasses will wear them happily because they do make a difference in their vision.

Here are a few ideas to help get your child to wear glasses

Start by having your child wear glasses for short periods during enjoyable activities, when your child will be having so much fun that he or she will forget about them. Use the glasses as part of reward times, such as when your child is watching his or her favorite video.

Choose a time when your child is rested and in a good mood to start requiring the glasses.

If your child takes his or her glasses off, be sure you put them back on in a firm but loving manner.

If your child learns that he or she has control over wearing the glasses, you may lose the battle. You do not want taking off the glasses to be an attention-getting tool.

Check the fit of the glasses. Stop by the optical shop if the frame loosens. As the child grows, the glasses may become tight or uncomfortable. Glasses that are poorly fitted can easily slip and slide down, and they then become useless.

Be positive. Parents’ and grandparents’ attitude can influence a child more than you think. Make glasses "cool" for your child: point out pictures of sports stars or entertainers who wear glasses. For very young children, "being just like mommy or nana" may be what counts.

Compliment your child for remembering to wear his or her glasses

Give your child some say in selecting the frame. Select three or four different frames that are acceptable to you, and then let the child pick the one he or she likes best.

Make the glasses a part of the child's daily routine. Put them on in the morning as your child is getting dressed and remove them before naps and bedtime. Enlist the teachers help by telling them your child's schedule for wearing glasses.

My child avoids wearing his glasses. He says it’s blurry with them on.

Children usually need a few weeks to get used to new glasses or to an updated prescription. Often children who have a negative perception of glasses will claim they see blurry to avoid having to wear them. Only if he continues to complain after one month of consistently wearing the glasses should they be rechecked to make sure that they are accurate.

Will my child need glasses for the rest of her life?Will she become dependant on them?

If your child has myopia or nearsightedness, then she will most likely need glasses for life or until she elects contact lenses as a teenager or refractive (LASIK) eye surgery as an adult (usually no sooner than age 18 to 21).

Since clear vision with eyeglasses is preferable to uncorrected vision, glasses wearers may find that they want to wear eyeglasses more often

Does watching TV, using the iPad or iPhone, or staring at the computer make the eyes or vision weak? Do these behaviors cause increased need for glasses or damage the eyes?

Watching television or working on computers or video display terminals (VDTs) will not harm your eyes. Often, when using a VDT for long periods of time, just as when reading or doing other close work, you blink less often than normal.

This reduced rate of blinking makes your eyes dry, which may lead to the feeling of eye strain or reflexive excessive blinking.

There is some evidence that excessive indoor reading or viewing of VDT activities can increase myopia, so outdoor activity after school can balance against this.

Are there vitamins, nutrients or dietary things I can do to reduce the glasses prescription for my child?

Almost all children in the United States have an adequate, well-balanced diet including vitamins that are sufficient to promote normal eye health and growth.

The need to wear glasses is unrelated to the nutritional state of the body. It is nevertheless helpful to ensure plenty of green, leafy vegetables for healthy eyes and eyesight.

Why does my child’s prescription continue to increase?

The prescription continues to increase because the eyes are growing. A naturally growing eye becomes more myopic or nearsighted. This is a normal developmental process, not a degenerative process.

Is there any vision therapy /exercise to prevent the need for glasses or to decrease the progression of the power of glasses?

There is no scientifically proven vision therapy that will prevent the need for glasses or decrease the rate of progression of the power of the glasses, or that will slow down eye growth, or reduce the strength of the glasses.

What is retina?

The retina is the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain.

There is a small area, called the macula, in the retina that contains special light-sensitive cells

What are the symptoms of retinal disease?



Sudden loss of vision

Distortion of vision

What is vitreous?

Vitreous is a thick transparent gel like substance that fills the eyeball between the lens and retina .It contains 99% of water and rest is a mixture of collagens, proteins, salts and glucose.

Do I require dilatation of eyes for retinal checkup?

Yes. For retina checkup, the pupil are dilated(expanded) with the help of drops which are instilled in both eyes. The drops are put every 15 mins for up to 5-6 times and it takes about 45 to 90 minutes to achieve the full effect. It’s after this the retina specialist examines your retina, this test is also known as fundus examination.

Can I drive after retina checkup?

No. Due to dilatation. Person experience blurring of vision and its not safe to drive.

I have diabetes, should I consult a retina specialist?

Definitely. Diabetes affects the microvasculature. Therefore it is important to check your retina.

When should I see a retina specialist?

Common symptoms of retinal disease are sudden loss of vision, distorted vision, floaters and flashes, peripheral shadows. Apart from this individuals who have DM,HT, high myopia should undergo retina checkup every 6-12 months. Anyone more than 40 years should get a retinal check up every year.

What are floaters?

Floaters are dark spots, thread or cob web like structures moving in the line of vision.

What to do if I have floaters and flashes?

Mostly floaters are harmless, but are warning signs to get eye check up. In DM and HTN can be due to blood in eye. After PVD chance of retinal break is there. So we should not avoid floaters.

Will floaters disappear?

They will gradually disappear and diminish over years.

What are the common causes of floaters?

Age, Diabetes are common causes of floaters.

What is retinal detachment?

It is a condition in which part of the retina is lifted or pulled from its normal position, and causes vision loss. If not treated leads to blindness. Therefore, retinal detachment is always considered an emergency

What are the causes of retinal detachment?

Retinal holes, retinal breaks, or retinal tears, and liquefaction of the vitreous humor. injury to the eye can cause retinal detachment

What precautions to be taken to prevent retinal detachment?

If u have sudden flashes or floaters consult your ophthalmologist immediately. I f you are have high myopia or if you have a family history of retinal problems be sure to have your eye examined regularly. Always wear safety eyewear during sports and other hazardous activities

Does RD occur in both eyes?

Detachment is more likely to occur if the other eye has the condition (such as lattice degeneration) associated with retinal detachment in the first eye. If only one eye suffers a serious injury or requires eye surgery then, of course, the chance of detachment in the other eye is less.

What are the risk factors for a retinal detachment(RD)?

Retinal detachment(RD) can happen to anyone at any age, however it is more common over the age of 40. It is commonly seen in people who had cataract surgery, myopia, eye injury, family history of RD, had RD in other eyes.

What is treatment of retinal detachment?

Treatment depends on configuration of retinal detachment multiple options like pneumatic retinopexy, scleral buckling, vitrectomy are available but type of RD and associated pathology decide the choice of surgery.

How long does it take for a detached retina to heal?

Improvement starts in 2 weeks after surgery. Retina may continue to heal for a year or more and it may take months to stabilise after surgery.

What is diabetic retinopathy?

It is a condition where high blood sugar levels damage the retinal blood vessels and cause leakage of fluid and blood in the retina.

Who is at risk of diabetic retinopathy?

Juvenile diabetes – more than five years

Adult onset diabetes – more than 10 years.

What is the treatment of diabetic retinopathy?

First advice is to control the blood sugar level.

Treatment depends on stages of diabetic retinopathy.

Initial stages may require regular retina checkup and good Blood sugar controlled.

In advance case retina laser is done to prevent bleed from new vessels.

More advance cases with persistent bleed and retinal detachment may need retina surgery.

Diabetic macular oedema may require Intravitreal injection (injection in the eye) and lasers.

How to prevent diabetic retinopathy?

Keeping your blood sugar and blood pressure under control can help prevent diabetic retinopathy Even controlled diabetes can lead to diabetic retinopathy, so you should have your eyes examined once a year.

How diabetes affects retina?

Diabetes affects the background retina and the macula. Background retinopathy – can be non-proliferative (NPDR) and proliferative (PDR). This may or may not be associated with diabetic maculopathy

What are the symptoms of diabetic retinopathy?

If the macula is affected, blurring of vision occurs. If the macula is not affected the patient will have no symptoms.

What is non proliferative diabetic retinopathy?

In this type, retinal blood vessels leak causing oedema and hemorrhage.

What is proliferative diabetic retinopathy?

In this type abnormal blood vessels are formed over the retina which causes hemorrhage and retinal detachment.

Is diabetic retinopathy curable?

It is not possible to reverse the damage that has occurred unless it is detected in a very early stage. Treatment can slow the progression of vision loss.

How frequently eye checkup should be done for diabetic retinopathy?

It is advisable to get your eyes checked once in a year

How is diabetic retinopathy diagnosed?

By dilated fundus (retina) examination.

What happens when diabetic retinopathy is not treated?

It would result in blindness.

When to screen for retinopathy when a diabetic woman gets pregnant?

Screening should start from the first trimester since progression is very fast in pregnant woman

Should people with diabetic retinopathy change their diet?

A very well-balanced diet and certain food guidelines are recommended for people with diabetic retinopathy. Sugars and fats, which increase blood sugar levels, must be avoided.

What is macular edema?

Macular edema is a complication of non - proliferative as well as proliferative diabetic retinopathy (and of other diseases, particularly vein occlusions). It is a swelling of the macula (the central area of the retina) caused by leakage of fluid and blood through the walls of dilated blood vessels. Macular edema is the most common cause of vision loss.

What is pathological myopia?

When an eye has myopia greater than 8 diopters, the problem is known as pathological or high myopia. Degenerative myopia, also called malignant progressive myopia, causes progressive stretching and gradual damage of the retina, choroid, vitreous, sclera, and optic nerve. This type of myopia needs regular clinical evaluation. At this time, the progression of this eye disease cannot be stopped. However, some complications of degenerative myopia such as retinal detachment, macular edema, and glaucoma, can be treated.

What are the retinal complications in high myopia?

Peripheral retinal degenerations

Retinal tear

Retinal holes

Retinal detachment

When to follow up?

If you are asymptomatic follow up every 6 months. The symptoms of a PVD and retinal detachment are

flashing lights

a recent onset, increase or change in your floaters

a curtain effect coming down, up or across your vision.

It’s important if you notice any of these symptoms or any new symptoms that you have in your eyes checked immediately by an eye specialist.

What is lattice degeneration?

It is the peripheral thinning of retina in high myopia. . It can cause holes and tears of the retina causing retinal detachment.

What are the symptoms of lattice degeneration?

Lattice degeneration ismostly asymptomatic. But if the patient sees any flashes or floaters it may be a warning sign of a tear or hole which has to be treated immediately to prevent retinal detachment.

Is treatment required for lattice degeneration?

If you are asymptomatic both eyes, there is no family history of retinal detachment they need not be treated. But if there is a development of tear, laser is adviced.

Can high BP affect retina?

Uncontrolled high blood pressure can damage the retinal vessels causing hypertension retinopathy. It causes edema, hemorrhages, occlusion of the retinal vessels leading to permanent retinal damage and vision loss. Hence it is prudent to keep your blood pressure under control and check your eyes yearly.

What is the treatment for hypertension retinopathy?

Controlling high blood pressure prevents changes in the blood vessels of the eye, as well as in other organs like the heart, kidneys and brain. Therefore, controlling high blood pressure is the only treatment for hypertensive retinopathy. The patient needs to follow a healthy lifestyle and adhere to the appropriate medical drug treatment .

What is age related macular degeneration (ARMD)?

It is the degenerative condition of the retina in which the central area of the retina responsible for central vision, the macula is affected

Will both eyes be affected?


What are the symptoms of ARMD?

What are the symptoms of ARMD?
p>Appearance of blurry spot, distortion of images, seeing wavy lines, sudden loss of central vision. If any of the above symptoms are present consult your ophthalmologist immediately

Is ARMD curable?

No, but treatment can slow or even stop the progression of the wet form, so the earlier you're diagnosed, better the improvement .

What is the treatment for ARMD ?

For dry armd- vitamin supplements

Wet armd- photodynamic therapy and intravitreal injections

What is a macular hole?

A hole develops in the macula, due to the vitreous gel inside the eye pulling on the retina. This vitreous gel tends to shrink as we get older causing traction. In most cases, macular holes can be surgically repaired, providing they are treated early.

How a macular hole treated?

Surgery is the treatment for macular hole. It is better to get operated within six months of it being found. The longer a hole is left, it is difficult. To successfully close the hole. In most cases, surgery will stop the vision problems getting worse. Most people will notice some improvement in vision, and more than 50% of cases will gain sufficient vision to allow driving and reading. It is difficult to restore perfect vision

What is retinal vein occlusion?

Retinal vein occlusion, is a blockage in the veins of the retina. There are two main types: branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). A blockage in both is thought to be caused by pressure on the vein from outside The most common cause of these is high blood pressure.

What are the symptoms of retinal vein occlusion?

Patients with both branch and central retinal vein occlusions usually describe a sudden painless loss of vision in one eye that may affect near and distance vision... it is very important to be checked immediately.

What is the treatment for retinal vein occlusion?

Treatment used in retinal vein occlusions. These include

Intravitreal injection

Laser photocoagulation

Vitrectomy surgery

Choice of treatment depends on clinical findings.

Branch retinal vein occlusions usually occur in people over 50 years old and are more common in people with high blood pressure (hypertension. Central retinal vein occlusions also occur in the same age group and are associated with high blood pressure, smoking, and glaucoma.

What is OCT?

Optical coherence tomography is a non-invasive diagnostic test used for imaging of retina. it helps in early detection of any disease. It is used to diagnose macular disorders like ARMD, macular edema, macular hole, CSR.

What is FFA?

Fundus Fluorescein angiography is a procedure to examine the tiny blood vessels in the eye.A dye called fluorescein is injected in your arm and serial photographs of eyes are taken. Dye highlight the blood vessel in the back of eye.

What is ocular migraine?

Visual problems associated with migraines are known as ophthalmic migraines, or ocular migraines, changes also may take place in blood flow to the area of the brain responsible for vision (visual cortex or occipital lobe).

Resulting ophthalmic or ocular migraines commonly can produce visual symptoms even without a headache.

Resulting ophthalmic or ocular migraines commonly can produce visual symptoms even without a headache.

What are symptoms of ocular migraine?

Typically you will see a small, enlarging blind spot (scotoma) in your central vision with bright, flickering lights (scintillations) or a shimmering zig-zag line (metamorphopsia) inside the blind spot.

The blind spot usually enlarges and may move across your field of vision. This entire migraine phenomenon may end in only a few minutes, but usually lasts as long as about 20-30 minutes.

What is the treatment for ocular migraine?

They cause no permanent visual or brain damage and do not require treatment.Still, always consult your eye doctor when you have unusual vision symptoms, because it’s possible that you have another condition requiring treatment, such as a detached retina, which should be checked out immediately

What is night blindness?

Blindness refers to difficulty seeing at night or in poor or dim lighting situations. The main indication of night blindness is difficulty seeing well in dark or dim lighting, especially when transitioning from a brighter to a lower light environment, like walking from outside into a dimly lit room.

Many experience difficulty driving at night, particularly with the glare of the streetlights or the headlights from oncoming traffic

What are the causes of night blindness?

Night blindness is a condition that can be present from birth, or caused by a disease, injury or even a vitamin deficiency.

Retinitis Pigmentosa – a genetic condition in which the pigmented cells in the retina break down causing a loss of peripheral vision and night blindness.

Is nightblindness is hereditary?

Yes. Nightblindness due to retinitis pigmentosa are hereditary in nature.


Dilated fundus examination and ERG (signals from retina are recorded) is done to confirm RP.

What is the Treatment for RP?

Vision loss due to RP is irreversible .

Low vision aids and visual rehabilitation are advised by the specialist.

What is the retina?

The eye is a hollow sphere, and the retina the inner lining of the eye wall. It is the structure responsible for capturing visual information and sending it to the brain. There are multiple layers to the retina.

The blood vessels which supply oxygen to the retina lie in the innermost layers.

What is retinopathy of prematurity (ROP)?

ROP is a disorder of the blood vessels of the retina (the light sensitive part of the eye) that occurs in some premature babies. ROP is one of the leading causes of blindness in children.

Which infants are at risk for ROP?

In general, ROP is a disease affecting the youngest, smallest and sickest infants. Typically, this includes infants born earlier than 32 weeks of gestation and under 1500 grams (about 3.3 pounds). The smaller and more premature the infant, the greater the risk.

How does an infant get ROP?

It takes a full term (40 week) pregnancy for the blood vessels which will supply oxygen to the retina to fully develop. The blood supply to the retina starts at the back of the eye at 16 weeks of gestation. The vessels gradually grow over the surface of the retina to reach the front edge at about the time of birth.

When an infant is born early this process starts. There are a variety of reasons this occurs, but the most important ones in babies born today are the degree of prematurity and birth weight.

Once the blood vessels stop growing over the surface of the retina, a patch of retina ends up starved for oxygen. This leads to immature growth of retina.

Do all babies born prematurely get ROP?

No. In most infants (85% of those at risk) the blood vessels finish growing over the surface of the retina as they were supposed to, although finishing the job a few weeks later than the original due date.

Do all babies who get ROP require treatment?

No. In most infants the ROP will subside (regress) on its own.

What are the different stages of ROP?

Retinopathy of prematurity (ROP) has been divided into five stages. Stages 1 and 2 customarily get better on their own. Some eyes, however, go on to Stage 3 retinopathy of prematurity. Stage 3 ROP exists when these disturbing new blood vessels grow out from the ridge in the retina toward the center of the eye. If this blood vessel growth becomes severe and is accompanied by “plus” disease (enlarged and twisting blood vessels in the back part of the eye), the child may reach the point where treatment of the peripheral retina with laser (or rarely freezing) treatment is performed. When stage 4 or 5 ROP is reached, the retina is detached

Can ROP get better or heal on its own?

Yes – in fact most infants do. It is called " regression " of the disease, and occurs when the retinal blood vessels grow to cover and nourish the retina.

Can ROP lead to blindness?

Yes. Eyes which progress to stage 4 or 5 can go blind. This may happen even when a child is properly screened and is properly treated in a timely fashion.

What treatments are available for ROP?

Currently, the standard of care treatment for ROP severe enough to require it is destroying the retina without blood vessels with laser. On occasion, freeze-treatment is used to accomplish the same goal. By destroying the peripheral retina the goal is to save central vision so that the infant can have as normal vision as possible. Other experimental treatments are being studied as well – most notably a drug called Avastin (bevacizumab).

Once the retina detaches (Stage 4 or 5), there are surgical therapies which may be employed to salvage vision.

How are at-risk infants followed?

They are examined either at the bedside or by digital pictures, generally on a weekly basis.

Is my child out of risk in terms of ROP once she/he is discharged?

Usually not. Infants at risk for ROP are followed until 52 weeks after conception. Since most infants are discharged from neonatal intensive care well before that age, in general some exams are still necessary in the weeks following hospital discharge to ensure the best visual outcome for your child.

How important are follow-up visits for ROP?

Failing to keep follow-up appointments puts your child at risk of blindness.

When are infants with ROP treated?

Most infants requiring treatment for ROP are treated at about 35-36 weeks post-conceptional age (typical range 32-40 weeks).

What is the treatment procedure?

The baby’s eyes are dilated, a lid speculum is used to hold the lids open, and the peripheral retina is treated with the laser. Treatment can be done either under general anesthesia, or sedation with local anesthesia.

Is treatment for ROP painful?

With anesthesia it would be a painless procedure. There is no pain after the treatment is completed.

What is the treatment success rate?

On the order of 85% of eyes requiring laser are effectively treated.

What will my child’s vision be after treatment?

It depends on the stage and severity of ROP. The less scar tissue present at the time of treatment, the greater the potential for visual development. Eyes treated at stage 2 or 3 may see as well as 20/40 or better. Eyes at early stage 4 often see as well as 20/80 - 20/200. About half of eyes at more severe stages of stage 4 see better than 20/2000 (ambulatory vision). Ambulatory vision is defined as being able to see objects and move around a room without stumbling or bumping into obstacles. Surgery for stage 5 ROP is often done to preserve vision in the range of ambulatory vision to light perception.

What is the impact of the laser on a child’s field of vision?

Peripheral vision (“side vision”) is usually reduced by laser treatment. Some side vision is sacrificed in the interest of preserving central vision – what we all use to read, drive, etc

What if treatment fails?

When stage 4 or 5 ROP is reached, the retina is detached and other therapies can be performed. One such therapy is scleral buckling, which involves encircling the eyeball with a silicone band to try and reduce the pulling on the retina. The most commonly performed surgery is vitrectomy (removal of the gel-like substance called the vitreous that fills the back of the eye). Sometimes the removal of the lens as well is required if the retina is touching the back surface of the lens, which would make it impossible to enter the eye.

What happens once the ROP regresses?

ROP is a lifelong disease, whether it resolves after treatment or gets better (regresses) on its own. Formerly premature children and adults require ongoing care for near sightedness (myopia), amblyopia (“lazy eye”), retinal detachment, and early cataract.

Does my child have any activity limitations because of ROP?

Usually not. Most children with regressed ROP live normal lives. On occasion, children with more advanced stages of ROP may have limitations with regard to sports and other activities.

How often should a child needs follow up?

Its depends on the stage of ROP,usually 4-6months follow up is advised initially. As the condition stabilize yearly follow up is compulsory.

What is squint (strabismus)?

Squint is a mis-alignment of the two eyes where in two eyes are not looking in the same direction. This misalignment may be constant, being present throughout the day, or it may appear sometimes and the rest of the time the eyes may be straight called as intermittent squint

What causes squint?

The exact cause of squint is not known. Six muscles control the movement of each eye. Each of these muscle acts along with its fellow in the other eye to keep both the eyes aligned properly. A loss of coordination between the muscles of the two eyes leads to misalignment

Refractive error -hypermetropia (far sightedness) or an eye muscle paralysis may lead to deviation of the eye. Poor vision in an eye because of some other eye disease like cataract, etc. may also cause the eye to deviate.

Any trauma or injury to eye can lead to squinting of eyes .

Therefore it is important in all the cases of squint, especially in children, to have a thorough eye checkup to rule out any other cause of loss of vision.

What are the symptoms of squint?

In a child, the parents may notice the deviation of eyes.Adults may notice double vision, or misalignment of the eyes.


An esotropia is the medical name for a convergent squint where one eye turns in towards the nose.


An exotropia is the medical name for a divergent squint where the one eye turns outwards.

Hypertropias and Hypotropias

These terms refer to vertical squints where one eye is higher (hypertropia) or lower (hypotropia) than the fellow eye. There are a number of different types of squint in each of these three groups, which have their own individual characteristics and treatments.

Paralytic Squints

There are three nerves which send signals to the six eye muscles, these are the third, fourth and sixth cranial nerves. Damage to these nerves as result of poor blood supply to the nerve, pressure on the nerve or head injuries will cause limited eye movements and a squint.

How is squint diagnosed?

The squint is diagnosed by the ophthalmologist by special tests performed in squint clinic to confirm the presence of squint, and find out the type of squint.

In some cases there may be a false appearance of squint due to broad nasal bridge in a child. This is called as false squint.

When should the squint be treated?

In a child, the treatment of squint should be started as soon as possible to prevent amblyopia. The younger the age at which amblyopia is treated; the better is the chance of recovery of vision.

A delay in treatment may decrease the chances of getting a good alignment of the eyes and the vision.

What are the treatment options?


Patching/occlusion therapy

Penalisation ( which induces dilation of pupil relieves ciliary muscle spasm)


Can glasses correct squint?

If the child has developed squint due to refractive error. Wearing glasses may correct squint. This clear vision is very to prevent amblyopia, and maintaining the alignment of eyes after they have been aligned by surgery

Can yoga or exercise correct squint ?

No, yoga or general body exercise will not correct squint .there are special eye exercise offered by orthoptics clinic to relieve eye strain, headache symptoms and treat squint to certain extent.

Is surgery required to correct squint?

Treatment of squint generally requires eye muscle surgery. However, some patients may need glasses, prisms, medications, or may be best left untreated. Your ophthalmologist will decide whether u require a surgery or not.

What is amblyopia?

Amblyopia is the medical term for a “lazy eye”. The reduced vision in an amblyopic eye occurs even though there is no structural abnormality of the eye. Amblyopia is responsible for more visual loss in childhood than all the other causes of visual loss combined.

What are the causes of amblyopia?

Squints (strabismus)

When a child develops a squint their brain is able to ‘turn off’ the image from one eye, preventing them from experiencing double vision. This process is known as suppression. As a consequence of suppressing the image from one eye the connections between this eye and the brain do not develop in the normal way and the vision in this eye is reduced. This is known as strabismic amblyopia, because it has arisen as a result of a squint.

This type of amblyopia is more commonly seen in children with an esotropia (convergent squint) compared to children who have an exotropia known as divergent squint.

High Refractive error in both eyes.

Both eyes may be significantly longsighted and or one or both eyes may have a high degree of astigmatism. These conditions can result in amblyopia because of the blurred image they produce.

Unequal refractive error

The other common cause of amblyopia is when one eye is more long sighted, or (less commonly) short sighted than the fellow eye. The medical term for this unequal refractive error is anisometropia. This means that the more long or short sighted eye will be seeing a blurred image, compared to the fellow eye and the brain will choose to ignore this blurred image. In children with an esotropia their amblyopia is often due to a combination of their squint and unequal refractive error.

Deprivation amblyopia

Deprivation amblyopia is caused by anything that deprives a child’s eye of visual experience. Causes of deprivation amblyopia include cataracts (cloudy lens) and a droopy eyelid (known as a ptosis).

Why is it important to improve the vision in the amblyopic eye?

In children who have the potential to develop stereopsis, their 3D vision will be better if they have good vision in both eyes. Perhaps the most important reason for treating amblyopia is to ensure that the vision is good enough in the amblyopic eye to enable the person to drive a car, work and live independently if they were to loose the vision in their other eye in later life.

What is patching/occlusion therapy?

Squinting eye can become ‘lazy’ and result in reduced vision. Patching the ‘good’ eye will make the lazy eye work harder, which improves vision .

Patching does not treat the squint, although the unpatched eye will appear to be straight while the patch is worn when the patch is removed the squint returns to the pre-patching position. The patch is made from non-irritating material to prevent rashes, and spectacles are worn over the patch.

Why can’t I leave the patching until my child is older and I can reason with him/her?

Unfortunately by this time it is often "too late" for the patching to work. Vision is developing at its fastest rate in the early years of life.

I don’t want to do this to my child. It feels cruel?

It is also cruel to deprive them of the possibility of better vision in their weak eye. An untreated squinting eye can lead to a virtually "blind" eye.

This has consequences if the child should lose the sight of their good eye later in life through accident or eye disease.

Why can’t my child have an operation to improve the sight in their lazy eye instead of the eye patch?

A squint operation can only restore the use of the two eyes together and / or improve the appearance of the squinting eye. It does not treat the poor vision in the amblyopic eye, this can only be done by patching / atropine drops and / or glasses.

Is it worth me patching at all? A two-hour dose of patching has been recommended, but my child will only wear the patch for half an hour.

Yes, any patching is better than none at all and you may be able to gradually increase the length of time the patch is worn as your child’s vision improves.

Do I have to do the patching in one session each day? What do I do if I forget one day?

The patching can be worn continuously for the prescribed time or it can be split up eg. 2 hours continuously or two 1 hour slots – whichever fits best into your routine.

However, many parents find that splitting it up causes more "fuss" from the child! If you forget to patch one day try to patch for twice the recommended time the next day.

I have noticed the squint sometimes swaps over into the good eye. What should I do?

If the squint swaps into the good eye occasionally this is a good sign for the vision, it means that the vision is becoming more equal in the two eyes.

If the squint just swaps over occasionally keep patching for the recommended time.

If at any point you think that the good eye is turning more than the “bad” one then you should stop the patch and contact your eye clinic for advice.

How many hours a day will the patch have to be worn for?

There is good evidence that 2 hours of patching a day is as effective as 6 hours of patching for moderate cases of amblyopia (vision between 20/40 – 20/80 or 6/12-6/24).

In more severe amblyopia patching for 6 hours per day is usually recommended.

It has been shown that full time patching is no more effective than patching for 6 hours per day, even in severe amblyopia.

How long will patching be needed for?

The duration of patching will depend on the severity of the amblyopia, the age of the child and how well the child and their parents are able to stick to the prescribed patching regimen.

Will the improvement in vision be permanent?

In approximately 80% of children the visual improvement is maintained for at least a year after patching is stopped. Recurrence of the amblyopia is more likely to occur if patching is stopped Suddenly, if the amblyopic eye is much more long sighted than the good eye (anisometropic amblyopia) or when the amblyopia is a combination of strabismic and anisometropic amblyopia.

This is why it is important to continue monitoring the vision until the child is 8-9 years of age, so any recurrence of the amblyopia can be treated.

When is it too late to start patching treatment?

Although the connections between a child’s eyes and their brain are normally fully formed by the age of 8-9 years, occlusion therapy can still be successful up to the age of 14 in some cases.

What happens if the vision does not improve with glasses, patching and /or atropine penalisation?

Occasionally the vision in the amblyopic eye does not improve despite the fact that the glasses have been worn full time and patching and / or penalisation has been carried out as instructed.

When this happens the ophthalmologist will re-examine the back of the eye again to make sure that there is not a subtle abnormality of the optic nerve or retina (which might not have been apparent at the time of the initial examination), that could be the cause of the poor vision.

How often should a child should come for check up?

It depends on the severity of the condition. usually close follow up may require from 3-6 months


Mahathma Eye Hospital Private Limited
No. 6, Seshapuram,
Tennur, Tiruchirappalli-620 017.
Phone : 91-431-2740494 , 2740494, 2741198

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93447 77411

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