Presbyopia or aging eyes, is a condition that affects virtually every adult at some point in time after the age of 40. When this condition develops, it becomes more difficult to focus on things that are close up because the natural lens of the eye becomes resistant to changing its shape the way it does when we are younger. In addition, the muscles of the eye that control the shape of the lens become weaker. Until recently, this meant wearing eyeglasses with bifocal lenses. Today it is possible to treat presbyopia with multifocal contact lenses.
It is easy to see how multifocal eyeglass lenses work. Whether they are bifocal or trifocal, they either have distinct lines between the focal points or there is an obvious fade from one focal point to the next. Multifocal contact lenses work in much the way, but the change in thickness of the lenses is very gradual.
When looking at something farther away, the eye will focus on light waves passing through the thinner part of the lens while looking at things up close will bring the eye to see the image passing through the thicker area of the lens. Getting used to the differing focal thickness of the lenses may take a few days, but once accomplished, one will not even notice the change from far to near. Focusing will be practically automatic.
Multifocal contact lenses can be manufactured in different manners and focal patterns. One brand makes lenses that look similar to a bull’s eye pattern with the center being focused for near vision, a ring for far vision, a ring for near vision, and a ring for far vision.
Another brand uses an aspherical center focused for near vision and the rest of the lens for far. Still another manufactures one lens for wear on the dominant eye with focal setting one way and the other for wear on the non-dominant eye with the focal setting reversed.
Because of these differences in manufacture, it will be important to let your eye care professional know which brand you will want to purchase so that fitting can done accurately for the style of focus points used by that brand. Then, of course, there will be the determination of what strengths to set each point at.
It will also be necessary to make sure that each lens is placed into the correct eye when worn so that focusing will be easier to accomplish. Even normal eyes are not identical in measurements and lens thickness. Presbyopic eyes will not be either. This is why testing will be done to identify the dominant and non-dominant eye and each lens will each be fitted to one or the other.
Getting older used to mean that one had to wear glasses. Normally, it meant bifocals or, in extreme cases, trifocals. Today, science has progressed to the point that it is possible to treat aging eyes or presbyopia, with multifocal contact lenses and not tell the entire world that one is getting older.