glossary

Eyesight disorders that prevent a clear image from forming on the retina (myopia, hyperopia, astigmatism).

Distortions, related to astigmatism , that cause the inability of light rays entering the eye to converge (come together) to a single focus point on the retina . Aberration are divided into two main categories: higher-order and lower-order. Optical system image defects; rays of light emanating from an object-point fail to form a perfect image-point.

Surgical removal of tissue, typically using a cool beam laser