Prescription eyeglass specialty lensesWritten by Timothy Gorman
There are many different lenses that have been specially created for certain purposes and needs. An aspheric lens is one of lightest weights of all lenses. They are available in bifocal or single vision prescription eyeglasses. The Allyl Resin plastic lens is also very light in weight. They do not offer protection from ultra violet rays that other lenses offer. The best lens on market is High index plastic lens. It offers highest level of ultra violet ray protection. It is light in weight and thin. It is also most expensive lens to purchase, but by far it is highest quality lens, as well. There are also many different coatings that can be applied to your prescription eyeglasses. It can be done by lens manufacture or at most Optometrist offices'. Photo chromic coating adjusts to intensity of light that it is exposed to. The come in brown or gray tint, and are available in glass or plastic.
| | When should Prescription Eyeglasses be worn?Written by Timothy Gorman
A person should have their eyes examined by an optometrist every two years or every year after age of 60, to determine whether they need to wear prescription eyeglasses. Also, If any of following symptoms occur, then an eye exam needs to be scheduled. * If a person is having a hard time focusing in on objects. * If eyes are red or swollen for unknown reasons. * If unusual headaches reoccur while reading, watching Television or working on a computer. There are several different tests performed by an optometrist during a routine eye exam to determine whether prescription eyeglasses are needed. A glaucoma test is a simple, painless test. Glaucoma is a build up of fluid in eye that causes retina to have pressure. Glaucoma doesn't really have any symptoms, but over time can cause total vision loss. A peripheral vision test determines degree of side vision that a person has. Then there is Visual Acuity test, which is test that determines one ability to distinguish letter, shapes and number in various sizes and from various distances.
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