plastic frames are durable, can accommodate just about any sfx lens prescription, and are available in a wide theatrical 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 orange deformed, so they do not need to be adjusted as frequently as other types. nylon 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 sclera eyes (pd) measured, contact so that the optical lens centers of the lenses sfx will be in front of the patient''s pupils. bifocal heights also have to be measured with the chosen frame in place and 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.

plastic frames are durable, can accommodate just about any sfx lens prescription, and are available in a wide theatrical 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 orange deformed, so they do not need to be adjusted as frequently as other types. nylon 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 sclera eyes (pd) measured, contact so that the optical lens centers of the lenses sfx will be in front of the patient''s pupils. bifocal heights also have to be measured with the chosen frame in place and 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.

simultaneous lenses bring distant and near objects into focus at the same time. theatrical 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, 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 orange designed for mild nearsightedness, keravision intacs are placed in the periphery sclera of the cornea contact 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 lens and sfx success rate of 20/40 vision or better.