Bifocal lenses are eyeglass lenses that contain two distinct optical powers (prescriptions) within a single lens. The word “bifocal” literally translates to two focal points, and it describe for people who are tired of constantly switching between two pairs of glasses: one for seeing things far away and one for reading.

How Do They Work ?

A bifocal lens is physically divided into two parts to serve two different viewing distances:

• The Upper Part (Distance Vision): This is the larger, main area of the lens. You look straight through this section to see things that are far away, such as while driving, watching TV, or walking.
• The Lower Part (Near Vision): This is a smaller, distinct segment (often shaped like a small “D” or a half-moon). When you look down to read a book, look at your phone, or do close-up paperwork, your eyes naturally look through this lower window.

Why Do People Need Them ?

Bifocals are primarily prescribed for people who have both a distance vision issue (like myopia/nearsightedness) and presbyopia.

Presbyopia is an age-related condition that typically begins around age 40. It happens when the natural lens inside the eye becomes less flexible, making it hard to focus on close-up objects.