What Is Presbyopia?
Presbyopia is the age-related loss of flexibility in the crystalline lens of the eye that makes it difficult for you to see objects that are close to you. Even if you have had “normal” eyesight all your life, anyone over age 40 knows that our vision begins to change in a number of different ways. Between the ages of 40 and 60, the most obvious changes to our vision occur in the eye’s crystalline lens.
In people under 40, the crystalline lens is typically crystal clear, as the name implies, and is also soft and flexible. It is this flexibility that allows the lens to change its shape and alter its curvature. Like a zoom lens in a camera, this flexibility allows it to focus your vision at various distances - from far, to near, to arms length, to far or near again. Essentially, this flexibility allows us to see at all distances.
As we enter our 40s, the crystalline lens begins to lose its flexibility. This makes it increasingly difficult for us to change focus in order to see arms length or close objects, or reading material. This loss of flexibility is called presbyopia.
Presbyopia, which literally means "old eyes", is a normal and expected consequence of the aging process. People experiencing the start of presbyopia often notice that they have to hold close things further away to see them clearly. Presbyopia typically becomes noticeable between age 40 and 50 and progressively worsens through age 65.
Like hyperopia or farsightedness, if you have presbyopia, you find it difficult to clearly see objects that are close to you. However, presbyopia is related to the aging of your eyes, not to their shape or length. It is caused by the loss of elasticity and flexibility which is a normal part of the aging process - the loss that makes it increasingly difficult for your eyes to shift their focus from near objects to those further away. Although farsightedness and presbyopia are both associated with growing older, presbyopia develops in people with all types of refractive errors including nearsightedness, farsightedness and astigmatism.
Who Is at Risk for Presbyopia?
We are all at risk for presbyopia. It is a natural component of the aging process and is inescapable. Fortunately, it can be corrected through various methods.
What Are the Symptoms of Presbyopia?
Although presbyopia sometimes appears to sneak up on us, it actually occurs gradually over time. You may first notice it when you’re holding a menu or a newspaper further away from you. When you are holding a book close to you, the words may appear blurry and you may suffer from a headache or eyestrain. Since presbyopia is a progressive disorder, your near vision will continue to deteriorate until about the age of 65.
How Is Presbyopia Detected?
Presbyopia is detected in a comprehensive eye examination, which will include:
- Visual acuity test: Measures the ability to see at all distances
- Refraction: Uses a phoropter to measure vision correction using different strengths of optical lenses
How Is Presbyopia Treated?
Once presbyopia is confirmed, your eye doctor will discuss various treatment options, depending on what other refractive errors you have. If your distance vision is clear, you may only require reading glasses. However, if you also have myopia or astigmatism, you may require bifocal or multifocal eyeglasses to correct your vision. Some patients with myopia, depending on the strength of their distance glasses, can simply take them off to read.
Your doctor may also suggest contact lenses, including bifocal lenses. Some patients elect to try monovision - meaning one eye is corrected for reading and close work, while the other eye is corrected for distance vision. After a short period of adjustment, your brain is able to accommodate for the difference in a process called neural accommodation. The result is that you “read” with one eye and do things like drive or watch TV with the other. Some patients are able to adapt to monovision.
Some patients also consider refractive surgery to treat presbyopia. If you have presbyopia, it is possible to surgically correct your non-dominant eye for reading by changing the shape of your cornea. Your dominant eye would then be used for distance vision. However, the American Academy of Ophthalmology recommends that you first try monovision contact lenses to ensure that you are able to adapt.
Primary Eye Care Specialists at Kadrmas Eye Care New England
Meet our ophthalmologists and optometrists who specialize in primary eye care and general eye health: