Using optical lenses, all categories of eyewear can be divided into Rx eyeglasses and non-prescription ones. Even if there are lots of eyeglasses products used for fashion enhancement, it is undeniable that Rx eyeglasses are the original form. And the function or help offered by these prescription devices is irreplaceable. In general, Rx glasses refer to eyewear products that are used to correct certain vision problems, ranging from refractive errors, and presbyopia to poor computer eyesight. These glasses differ from regular sunglasses and protective goggles in use frequency and lens design. For a large number of Rx eyewear users, such a device is indispensible during daily life and they need it to stay on the face constantly. Sunglasses and protective goggles are needed only in special circumstances and while staying indoors they can be removed. Another significant difference between Rx glasses and sunglasses or goggles lies in lens design that the former type use lenses with specific powers. And according to different lens functions, Rx spectacles are now available in a couple of forms.

The most common form is certainly single-vision glasses, including myopia glasses, hyperopia glasses and presbyopia or reading glasses. Note that astigmatism is usually corrected by myopia or hyperopia glasses, so that there are no astigmatism glasses. As the names indicate, this form of Rx eyeglasses is capable of dealing with a single vision problem. Nowadays, an increasing number of children and adults need to wear these eyeglasses, in order to get clear vision. In particular, myopia glasses are most popularly worn by patients who can not see with their natural eyes things in distance clearly.

Another major form of Rx glasses is multifocal spectacles. Compared with single-vision glasses, multifocal spectacles are able to deal with more than one vision problem. This capability is contributed by the lenses which have multiple focal points, indicating the origin of the name. A common point among different types of multifocal glasses is that presbyopic correction will be firstly ensured. Except for those regular two forms of Rx eyeglasses, there are also prescription sunglasses and prescription safety glasses. These compound products prove that prescription lenses have been applied to sunwear and safety eyewear industries.

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