Presbyopia
A Closer Look
What is Presbyopia?
Presbyopia is a condition in which your eyes gradually lose the ability to see things up close.
It is not a disorder or disease but rather a natural aging process of the eye. Presbyopia literally means "old eye" in Greek.
You may start to notice presbyopia around the age of 40, when you begin to hold reading materials farther away from your face in order to see them more clearly. This familiar event is often the first sign of presbyopia, which, if left uncorrected, can cause eye fatigue and headaches.
What Causes Presbyopia?
When you are young, the lens in your eye is soft and flexible. The lens can change its shape easily, allowing you to focus on objects both close and far away.
After age 40, the lens becomes more rigid and cannot change shape as easily as it once did. As a result, it is more difficult for the eye to focus clearly on close objects. Reading and performing other close-up tasks such as threading a needle become very difficult.
No medications, supplemental vitamins or exercises can stop or reverse the normal aging process that causes presbyopia.
What Can Be Done to Correct Vision for Presbyopia?
Reading Glasses
Prescription eyeglasses help refract, or bend, light rays before they enter the eye to compensate for the loss of near vision. If you have no other refractive errors (such as nearsightedness, farsightedness or astigmatism), you may only have to wear eyeglasses when reading or performing close tasks.
Bifocals, Trifocals or Progressive Eyeglasses
If you already wear eyeglasses to correct other refractive errors, you may need bifocals or trifocals to correct for presbyopia. Bifocals provide correction for both near and far vision. Trifocals provide correction for near, intermediate and far vision.
Progressive lenses offer the same corrections as bifocals or trifocals. But unlike bifocals or trifocals, which have a distinct line between levels of correction, progressive lenses are made with a gradual change in correction levels from the top of the lenses to the bottom.
Contact Lenses
If you prefer to wear contacts rather than eyeglasses, there are two types of contact lenses available: monovision and multifocal lenses.
Monovision contacts correct one eye for distance vision and the other eye for close-up vision. Because you need to train your brain to use one eye for distance and the other eye for near vision, it usually takes some time to adjust to monovision. Some depth perception may also be lost with monovision.
There are many different types of multifocal contacts available. Multifocal contacts have different focus zones within each lens, allowing for both near and distance vision. These different focus zones may cause the vision to be less sharp when compared to a monofocal lens.
However, with this loss in sharpness comes the ability to be able to see at both near and distance. Most people can adjust to multifocal lenses, but they do not work for everyone.
Can Refractive Surgery Correct Presbyopia?
Some people choose refractive surgery to achieve monovision, where laser surgery corrects one eye for distance and the other for near vision, just as with contact lenses. You may wish to consider trying monovision with contact lenses before surgery to determine your ability to adapt to this correction.
The most appropriate correction for you depends on your eyes and your needs. Before deciding on a type of correction, you should discuss with your ophthalmologist (Eye M.D.) which one is right for you.
