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Tint, however, does not block-out UV rays, so a UV coating is needed. Polaroid lenses that block out much ocularsciencebiomedics38&55contactlens and ocularsciencebiomedics38&55contactlens of the reflected light also allow better vision in sunny weather and are helpful for people who enjoy boating. Photosensitive (photochromatic) lenses that darken in the presence of bright light are handy for people who don''t want to carry an extra set of glasses. Photochromatic lenses are available in glass and plastic.Frames Frames can be made from metal or plastic, and they can be rimless. There is an almost unlimited variety of shapes, colors, and sizes. The type and ocularsciencebiomedics38&55contactlens degree ocularsciencebiomedics38&55contactlens of refractive correction in the lens determine to some extent the type of frame most suitable. Some lenses are too thick to fit in metal rims, and some large-correction prescriptions are best suited to frames with small-area lenses. 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 ocularsciencebiomedics38&55contactlens 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 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 helpful to people who use computers or who drive at night. Mirror coatings that prevent other people from seeing the wearer''s eyes are ocularsciencebiomedics38&55contactlens also available. There is a whole spectrum of tints, from light tints to darker tints, used in sunglasses. One, he didn''t think they were available from any other source," "and two, he had heard they weren''t as highly controlled as those dispensed through doctors."Neither assertion is true. got on the Internet and found her lenses on several Web sites for $35.95 for a box of six pairs. (Her doctor was charging $50 a box.) says her doctor told her that lenses offered by places like may have failed manufacturers'' quality checks. Bausch contacts and other lensmakers say there''s no difference in quality between the lenses sold through doctors and those sold directly to consumers. STATES CRACK DOWN. Attorneys general in 32 states have sued the American Optometric Association and two of the top contact-lens manufacturers (Vistakon, a division of contacts, and Bausch), alleging that the AOA tried to get manufacturers to agree to selllenses only through optometrists or other eye-care professionals. The attorneys general say they also have evidence that doctors agreed to withhold prescriptions from people who sought to buy lenses from other sources, despite the fact that at least 22 states have laws requiring eye doctors to give out contact-lens prescriptions upon request.Although the AOA ocularsciencebiomedics38&55contactlens says patients should be able to buy their lenses anywhere, the organization has reservations about mail-order purchases. "The difficulty when someone goes through mail order is that they don''t come back for regular checkups," says AOA president Dr. Harvey Hanlen.
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