Bifocal Contacts
By Nancy Del Pizzo, Reviewed by Dr. Joseph T. Barr


Bifocal contact lenses are designed to give good vision to people who have a condition called presbyopia. The key sign that you're developing presbyopia is that you need to hold reading material, like a menu, further from your eyes to see it clearly.

Bifocal contacts are available in both soft and rigid gas permeable materials.

Today's bifocal contact lenses are even available in a disposable or frequent replacement wear regimen. That means you can have the convenience of throwing the lenses out at specified intervals and replacing them with fresh, new lenses. Disposable bifocal contact lenses first became readily available in 1999.

Bifocal contact lenses work much like bifocal eyeglasses:

They have two powers on one lens: one to correct distance vision, if that's needed, and the other to correct near vision. Some contact lens designs feature two "obvious" prescriptions, with the distance vision on the top of the lens and the near vision at the bottom, similar to a bifocal eyeglass with a line separating the powers. Other designs work more like progressive eyeglass lenses, where the different prescriptive powers are blended on different parts of the lens. Your eye learns to differentiate the proper power for the correct distance.

Different Bifocal Designs

These different designs for bifocal contact lenses are called simultaneous, concentric and alternating vision styles. Simultaneous vision designs fit centered on your cornea with both the distance and near prescription within your pupil area. Your own visual system learns to interpret the correct power choice depending on how close or far you're looking.

In a concentric design, the center portion of the lens has the distance power and the outside or periphery portion has the near power, or vice versa. Alternating vision designs work much like a bifocal eyeglass with a line in that the top of the lens has one power and the bottom has the other.

Contacts, But Not Bifocals

Bifocal contact lenses may not be for everyone. Because the eye needs time to adjust to sorting out the different powers, it takes some time to adjust to bifocal contact lenses. The amount of time it takes will vary from person to person. Likewise, some people will have visual needs that are not satisfied by the current variety of bifocal contacts.

If that's the case, you may still be able to wear contact lenses and see clearly, even if you have presbyopia. Your doctor may recommend monovision as an option. With monovision, you wear one contact lens with one power to correct distance vision and the other contact lens with one power to correct near vision. The distance vision lens is usually worn in your dominant eye.

While monovision may appear to be an unusual choice, most people actually accommodate well to it, and eventually don't even notice that each eye is responsible for a different part of their vision. Because each lens has only one power, your doctor can prescribe any of the currently available spherical lenses for monovision, including all of the current disposable lens options.

The Limitations of Monovision

The down side is that each eye works more or less alone with monovision rather than binocularly, meaning you may have to adjust your head position more often to see. You also may lose some depth perception.

Many eye care professionals have free-trial programs in place where you can try a bifocal contact lens or even monovision to see if either will work for you. Visit your eye doctor to determine if bifocals or monovision make sense for your eye care needs and to identify the best lens design for you.