rli + rigid contacts

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Glass was the first material to be used rli for lenses lenses, and + was used rigid for several hundred years before plastic was introduced. The contacts and rli 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 rigid refraction, so it wasn''t suitable for people contacts with large refractive errors. A plastic called CR-39, introduced in the 1960s, was more suitable. Today, lenses wearers can also choose between polycarbonate, which is the most impact-resistant material available for eyewear, and polyurethane, which has exceptional optical qualities and an index of refraction of up to 1.66, rli much higher than the conventional plastics used for lenses, and even higher than glass. Patients with high prescriptions should ask about high index material options for their lenses. Aspheric lenses are also useful for high prescriptions.

Glass was the first material to be used rli for lenses lenses, and + was used rigid for several hundred years before plastic was introduced. The contacts and rli 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 rigid refraction, so it wasn''t suitable for people contacts with large refractive errors. A plastic called CR-39, introduced in the 1960s, was more suitable. Today, lenses wearers can also choose between polycarbonate, which is the most impact-resistant material available for eyewear, and polyurethane, which has exceptional optical qualities and an index of refraction of up to 1.66, rli much higher than the conventional plastics used for lenses, and even higher than glass. Patients with high prescriptions should ask about high index material options for their lenses. Aspheric lenses are also useful for high prescriptions.

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