contact lens for astigmatism - soft perm contacts

They are flatter and lighter than conventional lenses.There are many contact 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 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. lens 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 for 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 also available. There is a whole spectrum of tints, from light tints to darker tints, used in sunglasses.

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 astigmatism top half and near vision in the bottom half.Monovision An alternative to bifocal contacts, monovision lenses correct distance vision in one eye and near vision in the contact 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 rate of 20/40 vision or better.

Plastic frames are durable, can accommodate just about any lens prescription, and are available in a wide range of prices. They are also offered in a variety of plastics (including acrylic, epoxy, cellulose acetate, cellulose propionate, polyamide, and nylon) and in different colors, shapes, and levels of resistance to breakage. Epoxy frames are resilient and return to their original shape after being deformed, so they do not need to be adjusted as frequently as other types. Nylon lens frames are almost unbreakable. They revert to their original shape after extreme trauma and distortion; because of this property, though, they cannot be readjusted after they are manufactured.Fit The patient should have the distance between the eyes (PD) measured, so that the optical centers of the lenses will be in front of the patient''s pupils. Bifocal heights also have to be measured with the chosen frame in place and for adjusted on the patient. Again, this is so the lenses will be positioned correctly. If not positioned correctly, the patient may experience eyestrain or other problems. This can occur with over-the-counter reading glasses.