Bifocal (adjective)

Having two focal points, especially in a lens or eyeglass.

Origin:

From bi- + focal.

Examples:

1. Bifocal glasses have one lens for distance vision and another for reading.
2. The bifocal contact lenses have a different prescription for the top and the bottom.
3. The bifocal lens system allows the patient to see both near and far.
4. The bifocal design of the eyeglasses eliminates the need for separate reading glasses.
5. Bifocal glasses are particularly useful for people with presbyopia.