A cataract is a clouding of the lens inside the eye which leads to a decrease in vision. It is the most common cause of blindness and is conventionally treated with surgery. Visual loss occurs because opacification of the lens obstructs light from passing and being focused on the retina at the back of the eye.
It is most commonly due to aging, but has many other causes. Over time, yellow-brown pigment is deposited in the lens, and this, together with disruption of the lens fibers, reduces the transmission of light and leads to visual problems.
Those with cataracts often experience difficulty in appreciating colors and changes in contrast, driving, reading, recognizing faces, and coping with glare from bright lights.
Signs and symptoms
Signs and symptoms vary depending on the type of cataract, though considerable overlap occurs. reduction of vision. Glare,
Age is the most common cause, Lens proteins denature and degrade over time, and this process is accelerated by diseases such as diabetes and hypertension. Environmental factors, including toxins, radiation, and ultraviolet light, have cumulative effects,
Blunt trauma causes swelling, thickening, and whitening of the lens fibers. While the swelling normally resolves with time, the white color may remain. In severe blunt trauma, or injuries which penetrate the eye, the capsule in which the lens sits can be damaged.]
Ultraviolet light, specifically UV-B, has been shown to cause cataracts, and some evidence indicates sunglasses worn at an early age can slow its development in later life.
Cigarette smoking has been shown to double the rate of nuclear sclerotic cataracts and triple the rate of posterior subcapsular cataracts. Evidence is conflicting over the effect of alcohol.
Some drugs, such as corticosteroids, can induce cataract development.
Surgery is the current form of treatment, phacoemulsification is the most widely used cataract surgery. This procedure uses ultrasonic energy to emulsify the cataract lens. Phacoemulsification typically comprises six steps: