How Do Multi-focal and Bifocal Contact Lenses Work?

Multi-focal and bifocal contact lenses are a perfect choice for people who are affected by presbyopia. These lenses rid you of the need to switch eyeglasses or lenses for your near and farsightedness needs.

What is Presbyopia?

Many people experience a change in their vision after they cross the age of 40. One of the most common of these changes is the formation of a condition that makes it difficult for an individual to focus on things that are up close to them. It is a natural and gradual phenomenon and is known as presbyopia or short arm syndrome.

How do Multi-focal and Bifocal Contact lenses Help With Presbyopia?

Multi-focal and bifocal contact lenses work for both near and distant vision. They correct the vision by providing you with multiple focal points. The ability of these lenses to accommodate more than one prescription makes them a popular and effective choice for people with vision problems. Bifocal contacts have focal points for near as well as farsightedness, while multi-focal lenses have an additional intermediate focal point as well. Multi-focal and bifocal contact lenses are also useful in correcting astigmatism.

Types of Multi-focal and Bifocal Contact Lenses

All bifocals are multi-focal, but not all multi-focal are bifocal. The multi-focal lenses have a range of powers (like progressive eyeglasses) through which they cater to vision issues of multiple distances. There are lenses that offer intermediate, near, and far vision simultaneously or at the same time, and there are multi-focal contacts that allow you to switch between powers with the movement of pupils.

Multi-Focal Lens Designs

Aspheric lenses hold both near and far powers on their central areas. They allow the eyes to ignore objects that are placed far from you when you focus on the near objects and vice versa. You can find aspheric designs in most of the soft disposable lenses available in the market.

Concentric or annular lenses have the near focal points on the center while the distant ones are on the outer ring area, or it can be the other way around. The former type works better for people with large pupils, while individuals that have small pupils are better off with the latter kind. Soft and RGP lens materials commonly use concentric designs.

Segmented lenses are bifocal and have a separation line on them that segments near and far vision correction. The users of these lenses benefit from their distance power when they are looking straight and the near power when their eyes are looking through the part below the segment line. These lenses are made of RGP material and are smaller than soft lenses, making it a difficult task to find the line on them. You can get these lenses custom-made with an additional segment for your intermediate vision needs. The third segment is a small one that is shaped like a ribbon.

Multi-focal and bifocal contact lenses are a great choice if you suffer from presbyopia. With the advancement in technology, you do not have to wear eyeglasses with a clearly-visible line on their center.