trifocal glass

См. также в других словарях:

• trifocal — Having three foci. See t. lens. * * * tri·fo·cal ( )trī fō kəl adj 1) having three focal lengths 2) of an eyeglass lens having one part that corrects for near vision, one for intermediate vision (as at arm s length), and one for distant vision… …   Medical dictionary

• trifocal — I. adjective Date: 1826 having three focal lengths II. noun Date: 1899 1. plural eyeglasses with trifocal lenses 2. a trifocal glass or lens …   New Collegiate Dictionary

• Corrective lens — A bifocal corrective eyeglass lens A pair of contact le …   Wikipedia

• Lens — The transparent structure inside the eye that focuses light rays onto the retina (the nerve layer that lines the back of the eye, senses light and creates impulses that go through the optic nerve to the brain). The lens was named after the lentil …   Medical dictionary

• optics — /op tiks/, n. (used with a sing. v.) the branch of physical science that deals with the properties and phenomena of both visible and invisible light and with vision. [1605 15; < ML optica < Gk optiká, n. use of neut. pl. of OPTIKÓS; see OPTIC,… …   Universalium

• Glasses — Glasses, also called eyeglasses or spectacles, are frames bearing lenses worn in front of the eyes, normally for vision correction, eye protection, or for protection from UV rays.Modern glasses are typically supported by pads on the bridge of the …   Wikipedia

• Optician — An optician uses a lensometer to check eye glasses. An optician is a person who is trained to fill prescriptions for eye correction in the field of medicine …   Wikipedia

• Bifocals — are eyeglasses whose corrective lenses each contain regions with two distinct optical powers. Bifocals are most commonly prescribed to people with presbyopia who also require a correction for myopia, hypermetropia, and/or astigmatism.… …   Wikipedia

• Progressive lens — View through a progressive lens at some distance. In nor­mal use, a much smaller section of the glass is used, so that the dis­tortion is much smaller. Progressive spectacle lenses, also called progressive addition lenses (PAL), progressive power …   Wikipedia

• eye disease — Introduction  any of the diseases or disorders that affect the human eye (eye, human).       This article briefly describes the more common diseases of the eye and its associated structures, the methods used in examination and diagnosis, and the… …   Universalium

• lens — n. 1) (in anatomy) the transparent crystalline structure situated behind the pupil of the eye and enclosed in a thin transparent capsule. It helps to refract incoming light and focus it onto the retina. See also: accommodation 2) (in optics) a… …   The new mediacal dictionary