One of the most common eye diseases is Cataract. The most common form is the one called "senile cataract", which occurs due to natural aging of the eye, and mainly affects the past middle aged. Cataract also may be related to diseases, systemic or ophthalmic, or may be associated with long- term use of medications or injury (traumatic cataract), while rarely it is presented at birth (congenital cataracts).

A cataract is the clouding of the crystalline lens of the eye. The lens, which lies behind the iris (the colored part of the eye) is normally clear. Light passes through it to reach the retina, the back surface of the eye. As we age, this lens loses its original texture and begins to blur. Clouding makes lens reduce the light that reaches the retina. The clouding may become severe enough to cause blurred and gradual vision loss.

 Factors that may increase the chance of developing cataracts include blurring degree, the rate of progression, and the point of the lens that blurriness is appeared.

Treatment: 

Cataract is treated exclusively with surgery, where the blurry crystalline lens is removed and replaced with a clear, artificial intraocular lens (IOL).

The method used is called phacoemulsification. This is a technique, where the blurred crystalline lens is shattered through a small incision (2-3mm) using ultrasound, and it is aspirated. Through this incision, the IOL is also inserted.