At higher levels of nearsightedness the eye is typically excessive in length, with the retina stretched and secondarily thinned.
Correction requires thick lenses which add some image minification and distortion.
Contact lenses may be more difficult to wear, as they are also thicker. A small percentage of individuals have a progressive form of nearsightedness in which the walls of the eye continue to stretch with resultant increasing nearsightedness and risk of retinal damage. The breakdown into classification of severity relative to the prescription shown on the right is for illustrative purposes and somewhat arbitrary, as no technical categorization of this type exists. Lasik is becoming the method of choice worldwide for correcting higher degrees of nearsightedness. Lasik animation Select Vision Reference tm for more information about a vision disorder or procedure.