The crystalline lens in the structure inside the eye that focuses light onto the retina. A cataract is a clouding of the lens which causes light to be blocked or scattered as it enters the eye. The result is blurry vision (that cannot be further improved with corrective lenses), increased glare, and abnormal colour perception. Cataracts have many causes, including advanced age, exposure to radiation (such as UV),trauma/impact, poorly controlled diabetes, use of certain medications, and eye inflammation.

Most often cataracts are slowly progressing and many people may experience the early signs and symptoms of a cataract without requiring immediate treatment. The treatment for cataract is surgery to remove the cloudy lens and replace it with a clear plastic lens, which would require a consultation with an ophthalmologist who would perform the operation.