What causes low vision?
Though most often experienced by the elderly, people of all ages may be affected. Low vision can occur from birth defects, inherited diseases, injuries, diabetes, glaucoma, cataract and aging.

The most common cause is macular degeneration, a disease of the retina, the inner layer of the eye that senses light and allows you to see. Macular degeneration causes damage to central vision. It does not cause total blindness, because side [peripheral] vision is not affected.

Are there different types of low vision?
Yes. Although reduced central or reading vision is most common, low vision may also result from decreased side [peripheral] vision,loss of color vision or your eye might lose the ability to adjust to light, contrast or glare.

Different types of low vision may require different kinds of assistance. For example, people born with low vision have different needs from those who develop low vision later in life.

What is a low vision device?
A low vision device is an apparatus that improves vision. There is no one device that restores normal vision in all circumstances, so you may need different devices for different purposes. If possible, try a device before you buy it to see if it is useful for you. There are two types of low vision devices: optical and non-optical.

Is lighting important for people with low vision?
Correct lighting is as important as a low vision device. With no eye disorder, a 60-year-old person may need twice the illumination he or she needed at 20 to comfortably perform the same task. Some lighting tips. It should be close to your reading material for greatest visibility. High intensity lights with adjustable arms work well for this purpose

• Hat brims block annoying overhead light
• Absorptive lenses are useful in controlling glare
  
  

Cataract

What is cataract?
Cataract is the cloudiness of the normal human crystalline lens.

What are the symptoms of cataract?
Some common symptoms experienced by the patient include:
Decreased vision
Altered contrast sensitivity
Haloes around light
Polyopia(seeing more than 1 image)

What is the treatment of cataract?
Surgical extraction of the cataractous lens with an intraocular lens implantation is the only treatment available for cataract.

What are the types of cataract surgery?
They are extracapsular cataract extraction(ECCE)-with sutures, small incision cataract surgey(SICS)- 5mm incision with no sutures and the latest technique called phacoemulsification(2-3 mm incision size).

What are the different types of IOLs available?
IOLs may be either unifocal or multifocal. These again may be either foldable or non-foldable and either Indian or of the foreign type.

What are the benefits of phaco surgery?
These include:
Faster postoperative recovery
Smaller incision size
Less discomfort
Can be done under topical anaesthesia.

Do I need to get admitted?
No. Cataract procedures are now routinely done as a day-care procedure.

Will I need to wear glasses post surgery?
One would require glasses for near vision which would be prescribed after 2 weeks.

Retina

What is a retinal detachment
A retinal detachment occurs when the retina is pulled away from its normal position. the vision is blurred, like a camera picture would be blurry if the film were loose inside the camera.

A retinal detachment is a very serious problem that almost always causes blindness unless it is detected and treated early.

What causes retinal detachment ?
Usually the vitreous separates from the retina without causing problems, but sometimes the vitreous pulls hard enough to tear the retina in one or more places. Fluid may pass through the retinal tear, lifting the retina off the back of the eye, like a wallpaper that can peel off a wall.

The following conditions increase the chance that you might get a retinal detachment:

.    shortsightedness (myopia)
                     
     previous cataract surgery;

     glaucoma;

     severe eye injury;

     previous retinal detachment in the other eye;

     family history of retinal detachment;

     weak areas in the retina.

What are the warning symptoms of a retinal detachment?
These early symptoms may indicate the presence of a retinal detachment;

       Flashes of lights;
       Floaters;
       A gray curtain moving across your field of vision.

These symptoms do not always mean a retinal detachment is present; however,you should see your ophthalmologist as soon as possible. Your ophthalmologist [medical eye doctor] can diagnose retinal detachment during an eye examination where he or she dilates [enlarges] the pupils of your eyes with the use of eye drops. Some retinal detachments are found during routine eye examination.

Only after careful examination with an indirect ophthalmoscope can your ophthalmologist tell whether a retinal tear or early retinal detachment is present.

What treatment is needed?

Retinal tears

Most retinal tears need to be treated with laser or cryotherapy [freezing], which seals the retina to the back wall of the eye.

These treatments cause little or no discomfort and may be performed in your ophthalmologist’s office. Treatment usually prevents retinal detachment.

In some cases retinal tears can be observed without treatment.

Retinal detachments

Almost all patients with retinal detachments require surgery to put the retina back in its position.

Types of surgery

There are several ways to fix a retinal detachment. The decision of which type of surgery and anesthesia [local or general] to use depends upon the characteristics of your detachment.

In each of the following methods, your ophthalmologist will also locate any retinal tears and use laser surgery or cryotherapy around them to seal the tear.

Pneumatic retinopexy

A gas bubble is injected into the vitreous space inside the eye. The gas bubble pushes the retinal tear closed against the back wall of the eye.

Your ophthalmologist will ask you to maintain a certain head position for several days. The gas bubble will gradually disappear.

Scleral buckle

A flexible band [scleral buckle] is placed around the eye to counteract the force pulling the retina out of its place.

The ophthalmologist often drains the fluid under the detached retina from the eye, putting the retina to its normal position against the back wall of the eye. This procedure is performed in an operating room.

Vitrectomy

The viteous gel, which is pulling on the retina, is removed from the eye and usually replaced with a gas bubble. Your body’s own fluids will gradually replace the gas bubble. Sometimes vitrectomy is combined with a scleral buckle.

After surgery

You can expect some discomfort after surgery. Your ophthalmologist will prescribe any necessary medications for you. You will need to wear an eye patch for a short time.

Do not fly in airplane or travel up to high altitudes until you are told the gas bubble is gone. A rapid increase in altitude can cause a dangerous rise in eye pressure.

A change of glasses is often helpful after several months.

What are the risks of surgery?

Any surgery has risks; however, an untreated retinal detachment usually results in permanent severe vision loss or blindness.

Some of the surgical risks include:

  Infection;

  Bleeding;

  High pressure in the eye;

  Cataract.

Most retinal detachment surgery is successful, although a second operation is sometimes needed.

If the retina cannot be reattached, then the eye will continue to lose sight and ultimately become blind.

Will your vision improve?

Vision may take many months to improve and in some cases may never return fully. Unfortunately, some patients do not recover any vision.

The more severe the detachment the less vision may return. For this reason, it is very important to see your ophthalmologist at the first sign of any trouble.