Cataract is very common in old age. A cataract is a clouding that develops in the crystalline lens of the eye or in its envelope, varying in degree from slight to complete opacity and obstructing the passage of light. Although related to old age, it can sometimes be caused due to eye injury, exposure to radiation or may be a birth defect in children. The main reason normally found behind cataract formation is gradual discoloration or protein clumping. They commonly affect both eyes, but it is not uncommon for a cataract in one eye to advance more rapidly. Some factors that may lead to development of cataracts at an earlier age include excessive ultraviolet light exposure, diabetes, smoking, or the use of certain medications, such as oral, topical, or inhaled steroids.

The common symptoms of cataract are blurred vision, difficulty with glare, dull color vision, increased nearsightedness accompanied by frequent changes in eyeglass prescription, and occasionally double vision in one eye. If not taken care in time or untreated, cataracts can result in vision loss and blindness too.

Surgery to remove cataract is generally not suggested until vision becomes impaired. The standard cataract surgery is performed in a hospital where the cloudy lens is removed with an artificial lens. There are mainly three procedures of doing cataract surgery namely Phacoemulsification (Phaco), Extracapsular cataract surgery and Intracapsular cataract surgery.

Under the Phacoemulsification process, the surgeon makes a small incision in the surface of the eye or near the cornea. A thin ultrasound probe is inserted into the eye and vibrates, breaking the cataracts into fragmented pieces which are then suctioned through the same probe.

Extracapsular cataract surgery is performed in advanced cataracts where the lens is too dense to dissolve into fragments. The procedure requires longer incision on the side of the cornea and the lens is removed in one piece. Visual recovery is quite slower and discomfort is usually high as compared to phaco.

Intracapsular cataract surgery is even large than Extracapsular surgery. The surgeon removes the entire lens and the surrounding capsule all together. The cataractous lens is removed and replaced with a plastic lens (an intraocular lens implant) which stays in the eye permanently.

With advancements in laser and probe surgery, cataract patients can usually have their other eye problems corrected after the cataract has been removed.

Although there is no scientifically proven prevention for cataracts, but it suggested wearing protective eyewear after the surgery. Eye drops are often prescribed to remedy these problems.