Because computer glasses are used to see intermediate distance, the lenses are specially designed and they are unsuitable for driving or general purpose wear. The simplest computer glasses have single vision lenses with a modified lens power prescribed to give the most comfortable vision at the user's computer screen. These lenses relax the amount of focusing the eyes have to do to keep images on the computer screen clear and provide the largest field of view, reducing the need for head tilting and other unnatural posture changes during computer work.For older computer users, a specially designed progressive lens for computer use is sometimes a better option. Progressive lenses for computer use have a larger intermediate zone than regular progressive lenses for a wider, more comfortable view of the computer screen.Another option for presbyopic computer users is a lined trifocal, with a larger intermediate zone than regular trifocals. Still another possibility is an occupational bifocal, with the top part of the lens for intermediate vision (computer screen) and the bottom portion for near vision (reading).Your eyecare professional can help you decide which lens design will best suit your needs.
Studies have found that a majority of people who work on computers or hand-held devices experience some vision problems.Many of those people need special-purpose glasses with lenses adjusted to bring the computer screen sharply into focus.computer workers blink much less frequently than they would during a face-to-face conversation, and that leads to dry eyes at work.Computer glasses can take several forms.depending on the patient's age and visual needs,For adults under 40 who have not yet experienced the normal age-related loss of near-focusing ability, called presbyopia single-vision lenses are typically used for computer glasses.For people with presbyopia, doctors often prescribe single-vision, bifocal,trifocal or progressive lenses (without lines),depending on the wearer's need.Trifocals for computer work typically have a larger-than-normal intermediate zone placed higher in the lens for more comfortable viewing of the computer screen, but they still contain a small zone in the top of the lens for distance viewing.