What does the term "bifocal" mean?

The term "bifocal" specifically refers to lenses that have two distinct optical powers, enabling the wearer to see clearly at two different distances. This design typically combines a distance vision correction with a separate segment that allows for near vision correction. The common configuration seen in bifocals involves a visible line separating the two sections, with the upper part of the lens geared toward distance vision and the lower part intended for close-up tasks, such as reading.

This functionality allows individuals, particularly those who are presbyopic, to have a versatile solution that caters to both their distance and near vision needs without the need to switch between different pairs of glasses. Such intrinsic capability makes bifocal lenses a practical choice for many people as they age and experience changes in vision.