Eyeglasses and Contact Lenses
Definition
Eyeglasses and contact lenses are devices that correct refractive errors in vision. Eyeglass lenses are mounted in frames that are worn on the face, sitting mostly on the ears and nose, so that the lenses are positioned in front of the eyes. Contact lenses appear to be worn in direct contact with the cornea, but they actually float on a layer of tears that separates them from the cornea.
Purpose
The purpose of eyeglasses and contact lenses is to correct or improve the vision of people with nearsightedness (myopia), farsightedness (hyperopia), presbyopia, and astigmatism.
Description
Eyes are examined by optometrists (OD) or by...
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