The word “refractive” means something to do with the ability of the eye to create a clear, unblurred picture. There are many refractive problems, but the most common ones are short sight, long sight, astigmatism and presbyopia. Short sight, long sight and astigmatism are the result of the imperfect shape and/ or length of the eye.
At least one in five of us has a significant refractive problem. In a normal eye the cornea (the clear front of the eye) focuses light rays to a single point on the retina (the light sensitive area at the back of the eye which is like a film). The lens (the flexible part of the eye) only does the fine adjustment of the image. The result is sharp, precise sight.