Computer glasses differ from regular eyeglasses or reading glasses in a number of ways.
For greatest comfort, your computer screen and digital devices should be about 20 to 26 inches from your eyes. This is considered the intermediate zone of vision — closer than driving (“distance”) vision, but farther away than reading (“near”) vision.
If you are under age 40 and wear prescription eyeglasses, these glasses will provide clear vision at all viewing distances. But focusing on intermediate and near objects still requires effort by the ciliary muscle in your eye. The longer you stare at your computer and phone screens, the more fatigued this muscle and your eyes become.
If you are beginning to experience presbyopia, bifocals can provide clear distance and near vision. But intermediate vision (needed for computer use and seeing your smartphone) often remains a problem. Progressive lenses and trifocals offer some help for intermediate vision. But they often don’t have a large enough intermediate zone for comfortable computer work.
For these reasons, many people try reading glasses for computer use. But these, too, have limitations.
Generally, computer glasses have about 60% the magnifying power of reading glasses. (The optimal magnification depends on how far you prefer to sit from your computer screen and how close you hold your digital devices.)
Store-bought reading glasses are simply magnifying lenses in a frame.
Good computer glasses, on the other hand, do three things:
- Correct any refractive errors you have
- Provide the optimum amount of magnification for viewing your digital devices
- Reduce exposure to blue light
Also, custom computer glasses position the optical center of the lenses directly in front of your pupils when using your devices. This intermediate pupillary distance is not customized in store-bought reading glasses.
And store-bought reading glasses may provide little or no blue light filtering.
Custom computer glasses provide a wide, clear view of your digital devices, reduce focusing effort, and offer the added benefit of filtering blue-violet light.