Occurs when the cornea is too curved or the eye is too long. This causes light to focus in front of the retina resulting in blurry distance vision.
Occurs when the cornea is too flat in relation to the length of the eye. This causes light to focus at a point beyond the retina, resulting in blurry close vision and sometimes blurry distance vision, too.
Occurs when the cornea is shaped like a football (more curved in one direction than the other) and often occurs with nearsightedness and farsightedness. This causes light to focus on more than one point on the retina, resulting in blurry and distorted vision.
The Excimer laser removes microscopic layers of corneal tissue to change its shape, allowing light rays to focus more directly on the retina.