Nearsightedness
Eyeglasses:
Concave Lenses are used to move the focus point
back so it lands exactly on the retina.
Contact Lenses:
A myopia-correcting contact lens had rear surface
curve that matches the front curve of the cornea, and is thinner in
the center than in the periphery.
Laser:
Laser treatment works by optically ‘sculpting’
the desired correction into the collagen layer of the cornea. For
myopia correction, more sculpting is preformed in the center of the
treatment than in the periphery. This results in the removal of a
convex-lens-shaped portion of tissue, which is optically equivalent to
adding a concave lens to the eye’s optical scheme.
Nearsightedness (myopia) is the most common
optical condition in adults worldwide, affecting about 35% of the
population. In the nearsighted eye, light from distant objects focuses
in front of the retina, not on it; so a blurry image is perceived.
Concave lenses are used to correct this condition.
Correcting Nearsightedness by laser treatment involves precisely
sculpting the desired correction into the cornea. Glasses and contacs
work by adding a concave lens to the eye, whereas laser treatment
works by evaporating or subtracting a convex lens shape from the
cornea.