Cataract

A cataract is a cloudy or opaque area in the normally transparent lens of the eye. As the opacity thickens, it prevents light rays from passing through the lens and focusing on the retina. Early lens changes or opacities may not disturb vision. But as the lens continues to change, several specific symptoms occur:

• Blurred vision
• Sensitivity to light and glare
• Increased nearsightedness
• Distorted images in either eye may develop

There are three types of cataracts. Each is described by its location on the lens.

Nuclear Cataract

The most common type of cataract and the one associated with aging is called a nuclear cataract. It occurs in the centre of the lens. The most common symptoms are:

• Blurring or dimming of vision
• Glare
• Visual distortion
• Myopia or nearsightedness
• A temporary improvement in your reading vision sometimes referred to as “second sight”. This disappears as the cataract becomes worse.

Cortial Cataract

This condition begins as wedge shaped spokes in the cortex of the lens. The spokes extend from the outside of the lens. The spokes extend from the outside of the lens to the centre. When the spokes reach the centre, they interfere with the transmission of light and cause glare and loss of contrast. Many people with diabetes develop this type of cataract. Although a cortial cataract usually develops slowly, it may impair both distance and near vision so significantly that surgery may be suggested at a relatively early stage.

Subcapsular Cataract

Develop slowly and starts as a small opacity under the capsule, usually at the back of the lens. Significant visual symptoms may not appear until the cataract is well developed. Typical symptoms are glare and blur.

A subcapsular cataract is often found with:

• Diabetes
• High myopia
• Retinitis pigmentosa
• People taking stereoids

Treatment

The cataract may need no treatment at all if the vision is only a little blurry. A change in your spectacles prescription may improve vision for a while. There are no medications (at present), eye drops, exercises or glasses that will cause cataracts to disappear once they are formed. When you are not able to see well enough to do the things you like to do, cataract surgery  should be considered. Surgery is the only way to remove a cataract. Cataracts cannot be removed with a laser, only through a surgical incision. In a cataract surgery, the cloudy lens is removed from the eye. The focusing power of the natural lens is attempted to be restored by replacing it with a permanent IntraOcular Lens (IOL).

Even if the surgery itself is successful, the eye may still not see as well as you would like. Pre existing conditions may limit vision after surgery such as:

• Glaucoma
• Diabetic Damage
• Macular damage – Age Related Macularopathy (ARM)

If the eye is healthy, the chances are excellent that you will have a good vision following removal of cataracts.

The posterior capsule sometimes turns cloudy several months after the original cataract operation. If this blur occurs, a clear opening can be made with a laser.

Prevention

Studies show people living in high altitudes or those who spend a lot of time in the sun, smoke cigarettes develop cataracts earlier than others. Optometrists now recommend wearing sunglasses and a wide brimmed hat to lessen the eye’s exposure to UltraViolet (UV) light.