During cataract surgery, the eye's lens is removed, and an artificial lens is substituted, states the National Eye Institute. Surgery is required when vision loss from the cataract is severe and disrupts daily life. Up to that point, cataracts are treated with new glasses, better lighting, anti-glare sunglasses or magnifiers.
The eye's lens is primarily composed of water and protein, according to the NEI. Over time, some of the protein bunches up, clouding the lens. This blockage, called a cataract, causes less light to get to the retina, which interferes with vision. The healthy, clear lens becomes brownish, and vision is tinted as well. Cataracts often grow slowly, and vision decreases over time.