(lenses made from polycarbonate, dollar 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 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. 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 (m.d. or d.o.--doctor lens of osteopathy). prescriptions, if necessary, are then given sfx 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.

(lenses made from polycarbonate, dollar 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 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. 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 (m.d. or d.o.--doctor lens of osteopathy). prescriptions, if necessary, are then given sfx 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.

extended lenses in particular pose a much greater risk than daily wear lenses. though extended-wear lenses are extremely thin and allow some oxygen--necessary for healthy eyes--to reach the cornea, they are worn continuously, including at night while the eyelid is theatrical closed. bacteria can easily grow more easily under these conditions. twenty-one in 1,000 extended lens wearers develop infections as opposed to 4 in 1,000 daily soft lens wearers. to reduce this risk, eye care professionals now recommend removing extended lenses at night. in addition, newer versions of extended lenses being developed may offer increased oxygen exchange and pose less green risk. disposable lenses may also help to prevent infection, since the wearer is guaranteed a clean pair of lenses every few weeks or every dollar day.