What Is a Bifocal Lens?

According to the Department of Ophthalmology and Visual Sciences at the University of Illinois at Chicago, Benjamin Franklin invented bifocal lenses in 1784 as a way for people to be able to see objects that are both far away and in close range. Today, bifocal lenses are available to adults with presbyopia and for children and young adults who have problems with eye focus.

Definition

• Bifocal lenses contain two lenses in one piece. Each lens has a top segment and a bottom segment. Each segment has a different lens power, enabling you to clearly focus on distant objects and objects in close range.

Segments

• The top segment of a bifocal lens enables you to view distant objects that would otherwise be unclear. The bottom segment contains a different lens power that enables you to see objects at close range, most often for reading and computer work.

Considerations

• It might take time for you to adjust to wearing bifocal lenses. When looking through the bottom segment, objects appear closer than they are and appear as though they are located in a different place than they are. You must learn to automatically look through the appropriate part of the glass for different types of viewing.