Presbyopia - Topic Overview
What is presbyopia?
Presbyopia is the normal worsening of vision with age, especially near vision. As you approach middle age, the lenses in your eyes begin to thicken and lose their flexibility. The ability of the lens to bend allows our eyes to focus on objects at varying distances (accommodation). The loss of this ability means that vision gets worse and objects cannot be brought into focus. This typically becomes noticeable some time around age 40 when you realize that you have to hold a book or newspaper farther from your face to focus on it.
Normally, a muscle surrounding the lens in your eye expands or contracts, depending on the distance to the object you're focusing on. With presbyopia, the muscle still works, but it may not work as well. Also, the lens loses much of its flexibility and won't bend enough to bring close objects into focus. Images are then focused behind the retina instead of directly on it, leaving close vision blurred. Putting greater distance between the object and your eye brings the object into focus. For example, holding a newspaper farther from your face helps you see the words. For this reason, presbyopia is sometimes called "long-arm syndrome."
What causes presbyopia?
Presbyopia is a natural part of aging. As you grow older, the lenses in your eyes thicken. They lose their elasticity, and the muscles surrounding the lenses weaken. Both these changes decrease your ability to focus, especially on near objects. The changes take place gradually, though it may seem that this loss of accommodation occurs quickly.
What are the symptoms?
The main symptom of presbyopia is blurred vision, especially when you do close work or try to focus on near objects. This is worse in dim light or when you are fatigued. Presbyopia can also cause headaches or eyestrain.
How is presbyopia diagnosed?
Presbyopia can usually be diagnosed with a general eye exam. Your doctor will probably test your visual acuity (sharpness of vision), your refractive power (the ability of your eyes to change focus from near to far), the condition of the muscles in your eye, and the condition of your retina. He or she will probably also take measurements for glasses or contact lenses at the time of the exam.