A cataract refers to cloudiness that develops in the eye's clear lens. Cataract formation occurs when eye proteins clump and interfere with the lens's capability to send clear images to the retina. A cataract develops gradually and can form in one or both eyes. Cataracts are common among the elderly. The symptoms include poor night vision, blurry vision, and glare. The presence of cataracts in your eyes can cause eye health problems, which you need to avoid.