For anyone over the age of forty you can likely recall the frustration of having to hold your reading material further from your face in order to read the print clearly. For those of you who are near-sighted you likely have had to remove your spectacles in order to read a newspaper or label. Perhaps after reading for only a few minutes fine print became blurry or eyestrain and headaches became unbearable. All of these symptoms are due to a phenomenon called presbyopia.
Presbyopia typically begins between the ages of forty and forty-five. It becomes progressively worse until the approximate age of sixty. It is a natural aging process and it is not reversible. The exact mechanism as to how it occurs is not completely understood. Generally the focusing capabilities of the eye dissipate over time. As of now reading spectacles and bifocal glasses or contact lenses are the only forms of treatment.
Reading glasses are the first option I will discuss. Since they are focused for reading only they need to be removed when looking at a distance. For some people having to put their glasses on and off repeatedly can become a nuisance. Reading spectacles are easy to adapt to and relatively inexpensive.
The second option is bifocals and there are two types. The first type of bifocal is the traditional lined bifocal. They allow distance vision through the top of the lens and up-close viewing through the lower or bifocal portion of the lens. Lined bifocals are relatively easy to adapt to and are the lower priced bifocal type. Some people find intermediate distances such as the car dashboard or computer monitor difficult to focus on with the standard lined bifocal. This visual problem can be solved by lined trifocals which incorporate two bifocal lines on the lenses.
Most people do not like the visible bifocal line on the lenses for cosmetic reasons. Therefore the second type of bifocal available is the progressive or “no line” bifocal. This type does not have a visible bifocal line on the lens which is much more appealing. They correct for far away intermediate and up-close distances. Progressive bifocals can take longer for the patient to adapt to and are more expensive than lined bifocals.
Some people have trouble adapting to progressive bifocal lenses due to the distortion areas on the outer edges of the lenses. This produces a “swim-effect” for some people causing an unsettled feeling. Recently there have been technical advancements in the design of progressive lenses. Digitally manufactured progressive lenses are now available. These lenses have smaller distortion areas and more precise prescription control than traditional progressive lenses. The shape and size of the frame is taken into account when the lenses are fabricated.
There are also options available for contact lens wearers who are over the age of forty and are having trouble reading. One option is monovision contact lenses. This involves wearing a distance contact lens on one eye and a reading contact lens on the other eye. They are relatively inexpensive however depth perception may be hindered. A second option available is bifocal contact lenses. There is a highly variable success rate with these types of lenses.
Much like death and taxes presbyopia is unavoidable. As it stands now there is no proven method to prevent reverse or surgically correct the process of presbyopia. Consult your local optometrist or optician to determine which type of presbyopic correction fits your particular lifestyle.