Varifocal/Multifocal Contact Lenses for clear vision
Varifocals are the solution for correcting the vision problems associated with presbyopia. Many people realise they need varifocals (or bifocals) when they start experiencing blurred vision while doing close-up work like reading, sewing, using the computer or watching television.
Other symptoms of the condition include headaches or eye fatigue, as well as difficulty seeing in dim light.
Presbyopia and the need for varifocals is generally caused simply by the aging process. The symptoms generally start to appear between the ages of 40 and 50.
It's thought that people begin to experience presbyopia due to the fact that the lens of the eye continues to grow throughout their lifetime and that at some point the ciliary muscles that control the lens begin to have difficulty moving it.
Whatever the exact causes of this vision condition, a large proportion of adults will eventually need to correct the blurry sight caused by presbyopia. Advances in vision correction technology, mean that a variety of options exist, including contact lenses, spectacles and laser eye surgery.
If you have ever used varifocal eyeglasses, you'll have noticed that the lens has two different surfaces. The bottom part of the lens is designed to help the wearer see items that are up close, while the top part of the lens is for everything else. Just like the lenses in spectacles, varifocal contact lenses have two different prescriptions within a single lens.
This is called simultaneous vision and it works by allowing you to see objects that are near and far away at the same time. Your eye will easily adjust to this type of lens and you will be able to see clearly.
Multifocal contact lenses.
"Multifocal" is a catch-all term used to describe contact lenses that have different powers of vision in the same lens. Some examples of multifocals include concentric lenses, aspheric lenses and translating lenses. All of these lens types are designed to give you a clear field of vision in near, far and middle distances by shifting your gaze.
Multifocal Contact lenses are either weighted to stay in place, or are thinned out at the top and bottom to stay in the correct orientation in relation to your lids. They work on a 'simultaneous vision principle' in that both distance and near vision are in focus at the same time, and you learn to ignore one and see the other, depending on the task in hand. Multifocal lenses can come with a centre near or a centre distance design, and your optometrist will judge which is best for you. Many people are able to adjust to a multifocal lens within days. Others will not be able to tolerate them and may need to try alternative methods.Multifocal contact lenses now come in Dailies i.e Dailies Aquacomfort plus multifocal or 1 Day Acuvue Multifocal, in monthly formats i.e Biofinity Multifocal or even in multifocal lenses you can wear overnight for example Purevision Multifocal.
Multifocal contact lenses require careful fitting by an optometrist in order to get the correct powers to enable you to see comfortably at all distances. Sometimes the optometrist can make the smallest change to a power, either distance or near in the contact lens, and this can have a large impact on the quality of the users vision. Aftercare appointments to make these adjustments are very important to the overall chance of success.
Author: John Dreyer Optometrist Bsc(Hons), MCOPTOM, DipCLP
Created: 24 Apr 2015, Last modified: 17 Feb 2020