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Simultaneous lenses bring distant and near objects into focus at the same time. The center of the lens corrects distance vision; the outer part corrects near vision. * Segmented lenses correct distance vision in the top half and near vision in the bottom half.Monovision An alternative to bifocal contacts, contacts monovision lenses correct distance vision in one eye and near vision in the other. Modified monovision allows wearers to put a bifocal lens in one eye and a single-vision lens in the other.Implants Designed for mild nearsightedness, KeraVision Intacs are placed in the periphery of the cornea by an ophthalmic surgeon. Made of polymer, a type of hard plastic, they require no maintenance and can be surgically removed. The outpatient procedure has a 97-percent success companies rate of 20/40 vision or better. (Lenses made from polycarbonate, the same type of plastic used contacts for the space shuttle windshield, are about 50 times stronger than other lens materials.) Also, people at risk of receiving electric shock should avoid metal frames.People employed in certain occupations may be prohibited from wearing contact, or may be required to wear safety eyewear over the contact. Some occupations, such as construction companies or auto repair, may require safety lenses and safety frames. contacts Physicians and employers should be consulted for recommendations. Description Eyes are examined by optometrists (O.D.) or by ophthalmologists (M.D. companies or D.O.--doctor of osteopathy). Prescriptions, if necessary, are then given to patients for glasses. The glasses are generally made by contacts and companies an optician. A separate lenses-fitting exam is necessary if the patient wants contact, because an lenses prescription is not the same as a lenses contacts prescription. They are flatter and lighter than conventional lenses.There are many lenses and lens-coating options for individual needs, including coatings that block the ultraviolet (UV) light or UV and blue light which have been found to be harmful to the eyes. Such coatings are not needed on polycarbonate lenses, which already have UV protection. UV coatings are particularly important on sunglasses companies and ski goggles. Sunglasses, when nonprescription, should be labeled with an indication that they block out 99-100% of both UV-A and UV-B rays. There are anti-scratch coatings that increase the surface hardness of lenses (an important feature when using plastic lenses) and anti-reflective (AR) coatings that eliminate almost all glare and allow other people to see the eyes of the wearer. AR coatings may be particularly contacts helpful to people who use computers or who drive at night. Mirror coatings that prevent other people from seeing the wearer''s eyes are also available. There is a whole spectrum of companies tints, from light tints to darker tints, used in sunglasses.
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