There is a normal crystal clear, transparent lens located inside the eye. This crystalline lens gradually starts losing its transparency and become opaque of various grade.

Commonly due to old age-(Senile cataract).

Misuse of steroid tablet or steroid eye drops (steroid induced cataract)

Due to injury with blunt or sharp objects (traumatic cataract)

Infection to the mother at the time of pregnancy leading on to cataract to the new born (congenital cataract)

Eye infections caused by bacteria causing tuberculosis, leprosy etc., and other eye infections causing uveitis leads on to a cataract called complicated cataract.

Other conditions like night blindness, detachment of the retina also can cause complicated cataract.

Most cataracts develop slowly over time and affect people over age of 45 . in rare cases ,infants can have congenital cataracts due to infection in mother during pregnancy.

It could be a pre-senile cataract like premature greying of hair .It could be because of borderline nutritional deficiency in younger individuals.

Mainly due to aging ,other factors contribute for cataract progression are any kind of vitamin deficiency or malnutrition, prolonged exposure to sunlight(UV rays ) can initiate a cataract formation and also cause progression of cataract from one stage to another .

No ,cataract can be treated only by surgery(replacing the natural lens by IOL ).

There is hydration of lens fibres in cataract and formation of vacuoles through which when light passes there is diffraction causing photophobia or glare.

In case of penetrating injury, a sharp object pierces the cornea i.e. the black button of the eye, there is also simultaneous injury to the capsule of lens. This capsule is the protective covering of the normal lens. Once it is injured by a sharp object, the lens material also gets injured. It becomes immediately opaque called Traumatic Cataract.

Cataract is diagnosed by dilated comprehensive routine eye check .

Mild cataracts often cause little or no vision problems. Your doctor is probably monitoring your cataract to see if it worsens and more significantly affects your vision or lifestyle before recommending surgery.

Some cataracts never reach the stage where they need to be removed. But if your cataract worsens and you begin to have trouble seeing clearly for driving and other everyday tasks, it's probably time to consider cataract surgery.

The normal lens has got lens fibres. These fibres have a tendency to opacify under situations of low blood sugar levels (hypo glycemia ) or high blood sugar levels (hyper glycemia). In diabetic patients there is a rapid progression of cataract from immature to mature stage. Sometimes there is fluctuation in vision whenever there is fluctuation in the blood sugar levels which causes transient cataract.

When patient starts to experience cloudy ,foggy ,double vision and glasses no longer provides clear vision ,which lead to difficulty in performing daily activities when the cataract becomes matured ,it’s advisable to undergo cataract surgery .