[ad_1]
Computer glasses differ from reading glasses in their design for greater distance and reduction of screen glare. Prescribed glasses have custom lenses, while generic glasses may not fit all. Computer glasses may require a light tint or anti-reflection coating and specially designed lenses to address the eye’s focus on screens. Bifocals and progressive addition lenses are alternative solutions.
There are two main differences between reading glasses and computer glasses. The latter are designed to work at a greater distance. They also usually contain a material designed to reduce glare from the screen. An alternative to buying separate glasses for reading and computer use is to purchase specially designed bifocals.
Note that there is a big difference between general reading and computer glasses and those prescribed by an ophthalmologist or optician. Prescribed glasses will have lenses custom built to fit the specific deficiencies of the user’s eyes. Generic eyeglasses often simply contain magnifiers similar to those found in a magnifying glass. While these may suit many people, they won’t be a one-size-fits-all solution and may even do more harm than good.
Dedicated reading and computer glasses usually aim to meet different needs, especially in terms of distance. This is easy to observe in practice. Most people read books with their arms slightly bent, which means the book is about 18 inches from their eyes. For both visual and ergonomic reasons, the most common advice is that a computer screen should be within arm’s length of the reader, which can be up to twice the book’s reading distance. This requires a significantly different level of magnification and point of focus.
Another difference with computer glasses is the need to counteract the effects of glare and reflection from a computer screen. This is a particular problem with older CRT displays, but it’s still a problem with modern flat-panel monitors. This can be addressed with a light tint on the lenses or a special anti-reflection coating.
The lenses of computer glasses may also need to be specially designed to address the fact that the eye focuses differently with a screen. This is because, compared to the printed page, the contrast of characters against the background on a screen is much less defined. The lower definition causes the eye to need constant focus, even when looking at the same character.
There are several solutions to these differences, beyond just buying separate reading and computer glasses. One is to have special bifocals, with one part of the lens dedicated for reading the printed page and the other part customized for computer screen use. This is not an ideal situation for all users as, unlike reading a page from top to bottom, your eye is more likely to dart around when using a screen, which can require head movement when bifocal lenses are used. A more sophisticated solution is progressive addition lenses which, instead of simply being split into two lenses, gradually increase power by moving from the top of the lens to the bottom. This allows for easier adaptation to different types of visual material.
