The term cataract is used to describe the clouding of the natural lens of the eye. The vision dims because the cataract prevents light from passing beyond the lens and focusing on the retina.
A cataract is clouding or opacity of the lens inside the eye. It causes gradual blurring of vision and often glares. The Crystalline lens that is located inside the eye behind the iris, the colored part of the eye focuses light on the retina, which sends the image through the optic nerve to the brain.
Conversely, if the lens is clouded by a cataract, light is spread in such a way that the lens can no longer focus it properly, resulting vision problems. Clouding of the lens occurs due to changes in the proteins and lens fibers
Refractive surgery is a method for correcting or improving your vision. There are various surgical procedures for correcting or adjusting your eye's focusing ability by reshaping the cornea, or clear, round dome at the front of your eye. Other procedures involve implanting a lens inside your eye. The most widely performed type of refractive surgery is LASIK (laser-assisted in situ keratomileusis)where a laser is used to reshape the cornea.
Astigmatism can be corrected with refractive surgery techniques that selectively reshape portions of an irregular cornea to make it smooth and symmetrical. The result is that images focus clearly on the retina rather than being distorted due to light scattering through an irregularly shaped cornea.
