Katarakt, or cataract, is a condition that causes the lens of the eye to become cloudy, leading to blurred vision. This cloudiness can develop slowly over time and is often associated with aging, but it can also result from factors like injury, certain medications, or diseases such as diabetes. Symptoms of katarakt may include difficulty seeing at night, sensitivity to light, and seeing halos around lights. Treatment typically involves surgery to remove the cloudy lens and replace it with an artificial one, restoring clearer vision for the patient.