What type of lens is commonly used to correct both distance and near vision?

The designation of a lens as bifocal indicates that it contains two distinct optical powers to accommodate for both distant and near vision. Bifocals are specifically designed with a visible line that separates the two areas: the upper portion is typically used for distance vision, while the lower portion is used for near vision tasks, such as reading.

This design is beneficial for individuals who require assistance for both types of vision, enabling them to seamlessly switch between seeing objects at different distances without the need for multiple pairs of glasses.

While monofocal lenses only provide a single field of vision (either distance or near), bifocals effectively tackle the dual need. Trifocals include an intermediate vision zone in addition to the distance and near zones, while progressive lenses offer a gradual change in prescription from distance to near vision without any visible lines, providing a smooth transition. However, the straightforward design of bifocals specifically addresses the dual need in a more clear-cut manner, making them a popular choice for those who benefit from both deep and close-up vision corrections.