isotretinoin rx cheap Now-a-days, reading glasses are available in different styles and colours, thereby increasing the options to choose from. As with the regular prescription glasses, reading glasses are available in full rimmed, semi rimmed and rimless frames. The fashion conscious buyers, who want to try trendy colours with their reading glasses, choose the full rimmed frames. Apart from the fact that the rim offers protection to the lenses, it can be also used to flaunt unorthodox colours and unique designs. Semi rimless reading glasses offer the protection of the full rimmed glasses but are lighter than the later. Practitioners of a formal look find semi rimless reading glasses the perfect choice to emanate a professional appeal. Finally, rimless reading glasses, due to the absence of the rim, ensure a light-weight and the most comfortable eyewear experience. Though the lenses are unprotected, the erudite look of the rimless glasses has many buyers.
Reading glasses are also classified on the basis of the lenses. For patients who already had a vision disorder like myopia or hyperopia and then developed presbyopia, they will need more than one power on their lenses. Single vision reading glasses, unlike the bifocal and varifocal ones, are of not much use in this condition. Bifocal reading glasses have lenses with two different halves. The upper half is used for looking objects at a distance, while the lower half is used for reading purposes. As the two halves have different powers, the drastic change in the power causes image-jumps. On the other hand, the lenses of the the varifocal glasses have their lowest power at the top. Then, the power gradually increases as one proceeds downwards and is at its highest at the bottom. Just like the bifocal glasses, the upper and the lower halves are used for distance and close-range vision, while the intermediate region is used to view objects at an average length. As the power increases gradually, there are no image-jumps and the change in power is much gentler to the eyes of the user.