Planned-replacement lenses are daily discount contact wear lenses that are replaced on a regular schedule, which is usually every two weeks, monthly, or quarterly. they must also be cleaned. soft contact come in a variety of materials. there are also different kinds of rgp and soft multifocal contact available. monovision, where one lenses corrects for distance vision while the other corrects for near vision, may be an option for presbyopic patients. monovision, however, may affect depth perception and may not be appropriate for everyone. contact also come in a variety of tints. corrective are available that can change dark-colored eyes a different color. even though such lenses have no prescription, they must still be fitted and checked to make sure that an eye infection does not occur. people should never wear someone else''s contact. this can lead to infection contact or discount damage to the eye. aftercarelenses wearers must be examined periodically by their contact eye doctors to make sure that the lenses fit properly and that there discount is no infection. both infection and lenses that do not fit properly can damage contact the cornea. patients can be allergic to certain solutions that are used to clean or lubricate the lenses. for that reason, patients should not randomly switch products unless they speak with their doctor.

lensesesover discount 140 million people in the united states wear lenseses. people whose eyes have refractive errors do not see clearly without glasses, because the light emitted from the objects they are observing does not come into contact focus on their retinas. for people who are farsighted, images come into focus behind the retina; for people who are nearsighted, images come into focus in front of the retina. lenses work by changing the direction of light so that images come into focus on discount the retina. the greater contact the index of refraction of the lens material and the greater discount the difference in the curvature between contact the two surfaces discount of the lens, the greater the change in direction of light that passes through it, and the greater the correction.lenses can be unifocal, contact with discount one correction for all distances, or they can be correct for more than one distance (multifocal). one type of multifocal, the bifocal, has an area of the lens (usually at the bottom) that corrects for nearby objects (about 14 in from the eyes); the remainder of the lens corrects for distant contact objects (about 20 ft from the eyes).