What is cataract & types..

A cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupil. The lens works much like a camera lens, focusing light onto the retina at the back of the eye. The lens also adjusts the eye's focus, letting us see things clearly both up close and far away.

The lens is mostly made of water and protein and is transparent. The protein is arranged in a precise way that keeps the lens clear and lets light pass through it.

But as we age, some of the protein may clump together and start to cloud a small area of the lens. This is a cataract, and over time, it may grow larger and cloud more of the lens, making it harder to see. One reason why they clump together is because of denaturation of the lens protein.

When we age, the cellular contents of our cells start to die. When cells die, the pH of the lens drops slightly. This contributes to the denaturation of the lens protein.


Types of cataracts

There are 3 types of cataracts...
-subcapsular cataract
begin at the back of the lens. People with diabetes, high farsightedness, retinitis pigmentosa or those taking high doses of steroids may develop a subcapsular cataract.





-nuclear cataract
forms in the nucleus of the lens





-cortical cataract
forms in the lens cortex, gradually extends its spokes from the outside of the lens to the center. Many diabetics develop cortical cataracts.