Most eyeglasses are designed to optimize distance vision — usually defined as 20 feet away and beyond. Most bifocals and reading glasses are designed to give focused vision — about 14 inches from the eye. A computer monitor sits farther away than where your bifocal can focus but is too close for distance correction.
If you use a computer for long periods of time, you could consider “computer glasses.” These focus at the specific distance at which your computer monitor sits.
Alternatively, you could consider progressive bifocals. These glasses focus at multiple distances. With a slight change in head position, you can often find the spot in your glasses where you can clearly see the computer.
Ophthalmologist Richard E. Gans, MD