Bifocal Contact Lenses

Your eye care practitioner may recommend one of the two main categories of bifocal contact lenses:

Simultaneous vision
With simultaneous vision bifocals, you look through both the reading and distance portions of the lenses all the time. This means that whenever you look at an object, you see two images of it. One will be clear (from the portion of the lens most matched to the distance at which you are observing). The other will be blurred (from the other portion of the lens). Your brain learns to ignore the blurred image so that you see the other clear image.

Translating
Translating bifocals are similar in concept to bifocal eyeglass lenses. They have a thicker lower edge, which, when you look down to read, rests on the lower lid. As your eye turns downward to read, it looks through the reading portion in the lower part of the lens. In fact, even though they "translate," a portion of vision through this type of bifocal is of the simultaneous type.

If you wear bifocal contact lenses, they will normally perform optimally in bright conditions. Because bifocal lenses divide the light into two images, each of which will use about half of the available light, you may find that, in dimly lit conditions, seeing is more difficult with bifocal contacts. Driving at night may present more difficulty, for example.