What Is a Cataract?

The lens in the eye acts in a similar manner as the lens in a camera. The crystalline lens focuses the light that enters the eye as it travels to the retina. But sometimes the lens undergoes changes due to aging, disease or trauma and becomes a cataract.

Structure of the Lens

• The lens contains four layers; the capsule, the subcapsular epithelium, the cortex and the lens nucleus. Changes in any of these these layers may cause cloudiness in the lens.

Nuclear Cataract

• This is the most common type of cataract and occurs typically occurs with aging. The nucleus of the lens becomes hard and cloudy.

Cortical Cataract

• Cortical cataracts form when the cortex of the lens becomes cloudy; this type of cataract can affect both near and distance vision.

Subcapsular Cataract

• When a patch of cloudiness and deposits form under the capsule (either anterior or posterior capsule), this is called a subcapsular cataract; these types of cataracts can occur in people with diabetes or other diseases.

Other Types

• A traumatic cataract can form after an injury to the eye; some infants are born with a cloudiness in the lens which is called a congenital cataract.