Ophthalmic lens that utilizes a steepening of curves to incorporate corrections for distance vision through intermediate range, to near vision (usually in lower part of lens), with smooth transitions and no bifocal demarcation line.
Eyesight disorder caused by the aging of the crystalline lens, which with time thickens and loses its suppleness. As the crystalline lens becomes more rigid, it changes shape less easily and the subject sees less and less well in near vision. Refractive condition in which there is a diminished power of accommodation arising from loss of elasticity of the crystalline lens, as occurs with aging. Usually becomes significant after age 40.
A break in the posterior capsule of the lens, usually as a complication of cataract surgery. It may allow vitreous to move forward into the anterior chamber of the eye.