The lenses Council reports that 26 million Americans wear contact. Among lenses wearers, approximately 80% wear the soft type and 18% wear rigid gas-permeable lenses. The Council reports that about 11% of lenses wearers, approximately 2.8 million people, are under 18.InfantsThere are few instances when corrective lenses--lenseses or contacts--are prescribed dryeyescontacts for infants. However, when an infant develops cataracts , a condition known as infantile aphakia, contact may be prescribed following surgery. In 1993, the Journal of the American Medical Association reported that contact were safe and effective for use with infants following cataract surgery. Routine care of the lenses was easily learned by the baby''s parents or caregivers.

Glass was the first material to be used for lenses lenses, and was used for several hundred years before plastic was introduced. The crown glass used for lenses lenses has an index of refraction of 1.52.Optical-quality acrylic was introduced for lenses use in the early 1940s, but because it was easily scratched, brittle, and discolored rapidly, it did not supplant glass as the material of choice. Furthermore, it had a relatively low index of refraction, so it wasn''t dryeyescontacts suitable for people with large refractive errors. A plastic called CR-39, introduced dryeyescontacts in the 1960s, was more suitable. Today, lenses wearers can also choose between polycarbonate, which is dryeyescontacts the dryeyescontacts most impact-resistant material available for eyewear, and polyurethane, which has exceptional optical qualities and an index of refraction of up to 1.66, much higher than the conventional plastics used for lenses, and even higher than glass. Patients with high prescriptions dryeyescontacts should ask about high index material options for their lenses. Aspheric lenses are also useful for high prescriptions dryeyescontacts.