Presbyopia is when your eyes gradually lose the ability to see things clearly up close. It is a normal part of aging. In fact, the term “presbyopia” comes from a Greek word which means “old eye.” You may start to notice presbyopia shortly after age 40. You will probably find that you hold reading materials farther away in order to see them clearly.
What Causes Presbyopia?
Your clear lens sits inside the eye behind your colored iris. It changes shape to focus light onto the retina so you can see. When you are young, the lens is soft and flexible, easily changing shape. This lets you focus on objects both close-up and far away. After age 40, the lens becomes more rigid. It cannot change shape as easily. This makes it harder to read, thread a needle, or do other close-up tasks.
There is no way to stop or reverse the normal aging process that causes presbyopia. However, presbyopia can be corrected with eyeglasses, contact lenses or surgery. People who have trouble seeing both near and far may benefit from progressive lenses. In the future, presbyopia may be treated with eye drops. If you do not correct presbyopia, you may be bothered by headaches and eye strain.
If presbyopia is your only vision problem (you do not have nearsightedness, farsightedness or astigmatism), glasses may be all you need. Reading glasses help correct close-up vision problems by bending (refracting) light before it enters your eye. They can be bought without a prescription, but the specific power of reading glasses that you need should be determined by an eye exam.
Bifocals, trifocals or progressive Lenses
If you already wear eyeglasses for other vision problems, now you might need bifocals, trifocals, or progressive lenses.
- Bifocals correct for close-up and far vision. A line, which may or may not be visible, divides the lens. The bottom of the lens refracts light for close up vision. The top portion refracts light to allow you to see distant objects.
- Trifocals have three lens areas to correct for close-up, mid-range and far vision.
- Progressive lenses correct vision like bifocals and trifocals. But instead of a line that divides each refractive area, refraction changes gradually in the lens from top to bottom.
Some people prefer to wear contact lenses rather than eyeglasses. There are two types of contact lenses that help presbyopia:
- Monovision contacts. These correct one eye for distance vision and the other for close-up vision. You need to adapt to monovision lenses and train your brain to see this way. You may find you lose your ability to judge something’s distance or speed with monovision lenses.
- Multifocal contacts. These lenses have several rings or zones set at different powers. With this design, you are actually using both near and far vision at the same time. However, your brain learns to automatically select the right focus for what you want to see. You may find that using a multifocal lens makes your vision less sharp than when using a monofocal lens.
Prescription eye drop medication (pilocarpine hydrochloride ophthalmic solution) is now available to treat presbyopia. The drops work by reducing the size of your pupils. Your eyes can then adjust focus to see clearly up close. The eye drops are effective for up to six hours and you need to use them every day.
Refractive surgery. Some people decide to have surgery to achieve monovision. This can reduce their need for glasses for near and far objects. Using a laser, an ophthalmologist reshapes the cornea for clear far vision in one eye and close-up vision in the other. In many ways, this is like wearing monovision contact lenses. Your ophthalmologist may suggest that you try monovision lenses before having LASIK surgery. That way you can tell if monovision is a comfortable option for you.
Corneal inlays. There are also newer, tiny devices called corneal inlays, which help correct presbyopia. These are implanted in the cornea, at the front of the eye, during a minimally invasive surgical procedure, restoring close-up vision. Talk with your ophthalmologist to see whether you are a candidate for a corneal inlay and which type may work best for you.