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, contacts epoxy, cellulose acetate, sfx 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 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 theatrical the patient should have the distance between the glow eyes (pd) measured, in 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 adjusted on the patient. again, this is so the lenses will be positioned correctly. the 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 lens prescription, and are available in a wide range of prices. they are also offered in a variety of plastics (including acrylic, contacts epoxy, cellulose acetate, sfx 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 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 theatrical the patient should have the distance between the glow eyes (pd) measured, in 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 adjusted on the patient. again, this is so the lenses will be positioned correctly. the if not positioned correctly, the patient may experience eyestrain or other problems. this can occur with over-the-counter reading glasses.

(lenses made from polycarbonate, the same type of plastic used for the space shuttle windshield, are about 50 times stronger than other lens materials.) also, people at risk of dark receiving contacts 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 or auto repair, may require safety lenses and safety frames. physicians and employers should be consulted for recommendations. description eyes are examined by optometrists (o.d.) or by ophthalmologists sfx (m.d. or d.o.--doctor of osteopathy). prescriptions, if necessary, are then given to patients for glasses. the glasses are generally made by 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 prescription.