what is a cataract in the eye

A cataract is a clouding of the lens of the eye, which is typically clear. It causes vision to become cloudy, blurry, and less colorful. This clouding occurs when proteins in the lens break down and clump together, obstructing the passage of light through the lens and focusing on the retina. Common symptoms of cataracts include clouded, blurred, or dim vision, trouble seeing at night, sensitivity to light and glare, the need for brighter light for reading and other activities, seeing "halos" around lights, frequent changes in eyeglass or contact lens prescription, fading or yellowing of colors, and double vision in one eye. Cataracts are most commonly age-related, but they can also be caused by other eye conditions, past eye surgery, medical conditions such as diabetes, or long-term use of steroid medicines. Fortunately, cataract surgery is generally a safe and effective procedure, involving the removal of the cloudy lens and its replacement with an artificial lens called an intraocular lens (IOL) .