Concave lens: Short sight :: _________ : Long sight
Convex lens
Both myopia (short-sightedness) and hypermetropia or hyperopia (long-sightedness) are common eye defects that occur when the light does not focus on the retina of the eye. Both conditions are easily corrected using prescription glasses or contact lenses or in mild cases by laser eye surgery. For myopia, a concave lens (minus powered) is placed in front of a myopic eye, moving the image back to the retina and clarifying the image. Whereas hypermetropia or hyperopia can be corrected with a convex lens (outward facing) lens. This is placed in front of a hypermetropic eye, moving the image forward and focusing it correctly on the retina.