Considering the vast number of changes our bodies undergo as part of the normal aging process, one the most predictable, and one often considered a hallmark of middle age, is the onset of presbyopia. This is the very normal, progressive loss of the ability to keep the eyes in focus at close reading distances. The age of onset is typically late 30’s to early 40’s. There are rare exceptions, and some individuals do manage to hold out into their 50’s. Eventually, however, we all must accept this increasingly obvious complication. This problem can be especially distressing for those individuals who have been wearing contact lens corrections up to this time. Having spent 32 plus years assisting patients, family and friends cope with this change, I would like to offer some simple observations and suggestions for keeping contact lens wear as a functional option. These observations pertain to both rigid and soft contact lens wearers, but the vast majority of those affected now have probably been wearing soft contacts since the 70’s or 80’s.
Cheaters – Elegant Simplicity
Most contact lens wearers, especially those involved in recreational or competitive sports, are well-advised to stay with their current distance-correcting lenses and simply use inexpensive, commercially available reading glasses for close vision tasks. In the early stages of presbyopia reading assistance is usually needed only for certain situations, such as low lighting in restaurants and theaters, or for extremely small printed details, like maps and medicine bottles. With advancing age, as the reading issues become more profound, other options, such as multi-focal contact lenses, can be explored. The use of simple reading glasses retains the good distance vision from the old contact lenses and provides very effective near vision. As the presbyopia deepens, stronger reader powers will be required, and different powers will be needed for different working distances. Reading a book at 16 inches requires as stronger reading lens than working at a computer monitor at 22 inches. Cheaters are available everywhere, and can be a fun fashion accessory. They are also available in safety glass and sunglass designs.
Mono-vision – History Revisited
The old photos of historical figures wearing monocles depict a vision correction still widely employed today, especially among contact lens wearers. The long absence of functional multifocal contact lens options resulted in patients and their eye doctors seeking some means of dealing with presbyopia without the use of the stigmatizing reading glasses. The technique of correcting the vision in one eye for distance and the other eye for reading is called mono-vision. This acuvue ancient technique is very easy to try, especially with modern soft contact lenses, but it is poorly tolerated by the majority of patients who attempt it. Obviously, mono-vision will disrupt normal binocular vision and interfere with distance visual acuity and depth perception. Curiously, those who are able to tolerate the imbalance do surprisingly well for many years. Mono-vision must never be used by individuals requiring optimum distance vision and binocularity, such as commercial vehicle operators, pilots, or professionals involved with precise, near-point depth tasks. A simple trial in the eye doctor’s office can determine if this go-or-no-go application is viable.
Multi-focal Contact Lenses – Slowly Getting There
Multi-focal contacts have been available in rigid contact lens designs for over fifty years, but not until the fairly recent explosion of availability in soft lens configurations have they been a truly viable option for the huge population of emerging presbyopes. All of the major soft contact lens manufacturers have entered the multi-focal market. Lenses are available in a wide variety of materials, both conventional daily-wear and new, oxygen-permeable silicon materials. Even significantly astigmatic patients now have multi-focal lens options available to them. Virtually all of the new multi-focal designs employ a feature called simultaneous vision, wherein the eye is viewing through both the distance and near part of the lens all of the time. The different companies try different combinations and arrangements of the two optical zones, but there remains a significant similarity in all of the designs. Practically speaking, this means that the two distinct power zones inevitably get in each other’s way. The problem most frequently reported by my patients is a significant reduction in visual acuity during night driving, with annoying amounts of flare around lights. This results from the enlarged, dark-adapted pupil allowing more light to enter through the two conflicting zones of the contact lens. Some patients are much better able to cope with this than others. I have had some considerable success using a modern form of mono-vision, with a distance-only lens on one eye and a bifocal on the other. Fitting multi-focal contact lenses involves a great deal of necessary trial-and-error, and it is critical that there be significant communication between patient and doctor if there is to be a truly functional result.