How we see is important to understanding how vision correction works. When we look at an image, light passes through the outer most part of the eye called the cornea. From there, the light passes through our lens. The lens is responsible for focusing on objects, either in the distance or up close. Finally, this image is projected onto the retina, which transmits the image to the brain via the optic nerve. Imperfections in vision can be caused by any three of these areas (cornea, lens, or retina).

Most laser vision correction aims to perfect the image entering the eye by gently reshaping the surface of the cornea. These types of imperfections in our vision are known as refractive errors categorized into three types: nearsightedness, farsightedness, and astigmatism. Laser vision correction is an effective treatment for all of these types of refractive errors.