Cataracts are cloudy areas on the lens of the eye that lead to visual disturbances. If untreated, they can ultimately result in blindness.

The main signs and symptoms of cataracts include blurred vision, poor night vision, difficulty distinguishing colors, halos around lights, double vision, and light sensitivity. These visual disturbances worsen as the cataract develops.

Cataracts are diagnosed through an eye examination conducted by an ophthalmologist, who dilates the pupil and uses a slit-lamp microscope to examine the lens and the back of the eye. Although symptoms can aid in diagnosis, they may also indicate other eye conditions like glaucoma.

The main medical treatment for cataracts is surgery, during which the cloudy lens is removed and replaced with an artificial intraocular lens chosen by the surgeon. This procedure can also correct refractive errors that may have required corrective lenses.

Some evidence suggests that caffeine may help prevent and treat cataracts, and higher coffee intake is associated with lower risk. Although vitamins E and C and beta carotene have been studied for their antioxidant properties, the evidence does not currently support their use in cataract treatment, though vitamin B12 may have a role in prevention.

A higher intake of fruits and vegetables is associated with a reduced risk of developing cataracts. Additionally, vegetarian or vegan diets may lower this risk, potentially due to increased consumption of vegetables and legumes.

Research is ongoing into new medical treatments for cataracts, including antioxidants like N-acetylcysteine and oxysterols such as lanosterol, which may help reduce oxidation and stabilize lens proteins. However, there is still uncertainty regarding the effective dosages and the delivery of these treatments through topical methods like eye drops.

Cataracts are caused by proteins that clump together in the lens, which leads to cloudiness and discoloration that disrupts light filtration and vision. The primary cause is aging, particularly in people over age 60, and additional risk factors include genetics, smoking, diabetes, sun damage, and eye trauma.