optical lens glass lens

Specifications A lens is an optical device with perfect or approximate axial symmetry which transmits and refracts light. glass lens

    Lenses are used as prosthetics for the correction of visual impairments such as myopia, hyperopia, presbyopia, and astigmatism. (See corrective lens, contact lens, eyeglasses.)   Most lenses used for other purposes have strict axial symmetry; eyeglass lenses are only approximately symmetric. They are usually shaped to fit in a roughly oval, not circular, frame; the optical centers are placed over the eyeballs; their curvature may not be axially symmetric to correct for astigmatism. Sunglasses lenses may be designed to attenuate light without refraction.