Bifocal & Progressive Glasses Need Of Several People-tsumori chisato

Shopping-and-Product-Reviews Refractive errors in the eye have been a major concern for people of all ages. Earlier, people used to wear single vision glasses, but they were inappropriate for those who suffered from more than one refractive error. There are basically three types of vision errors which people normally have to deal with. They are described below: Myopia: In this type of error, the person faces difficulty to see distance objects. This is also called nearsightedness and this can be corrected by wearing corrective lenses. Hyperopia: Farsightedness which is known as hyperopia in medical terms. People suffering from this problem are unable to view close up things easily. Astigmatism: In this type of error, the person is unable to focus a point into a sharp focused image. Earlier the single lens vision glasses were prevalent but it was of no use to people suffering from more than one refractive error. Then bi-focal lenses came into the picture which was able to correct more than one refractive error. These types of glasses have visible lines on the lens and used to correct different vision problems. It means that at the bottom part of the glasses have different lens from the upper part. The lower part is usually fitted to correct farsightedness and enables people to view close up things clearly. People wearing these types of glasses can easily read and work on the .puter easily without any strain on the eyes. The upper part of the lens is used to correct shortsightedness and people can clearly view far away objects clearly. Actually, they contain two prescriptions, the top part is used for correcting distance vision and the bottom part is used for reading. Today, bi-focal lenses .e with UV coating and scratch resistant coating. There are several types of frames available in them and one can choose according to their preferences. Technological progress has invented progressive lenses which are better than the bi-focal lenses. The progressive glasses do not have a separate visible line in the lens. Visually they look better than the bi-focal lens but serve the same purpose. They look just like the normal glasses but have your prescription lens fitted in them. The wearer has a smooth transition in viewing far way and close up objects. One can buy these prescription glasses on online optical stores. There are cheap prescription glasses available and you can easily avail the huge discounts available on them. People can buy them with great convenience on online stores and get them at a price much less than the retail price. About the Author: 相关的主题文章: