Presbyopia is the gradual loss of your eyes’ ability to focus on nearby objects. It’s a natural, often annoying part of aging. Presbyopia usually becomes noticeable in your early to mid-40s and continues to worsen until around age 65.

You may become aware of presbyopia when you start holding books and newspapers at arm’s length to be able to read them. A basic eye exam can confirm presbyopia. You can correct the condition with eyeglasses or contact lenses. You might also consider surgery.
Presbyopia develops gradually. You may first notice these signs and symptoms after age 40:

A tendency to hold reading material farther away to make the letters clearer
Blurred vision at normal reading distance
Eyestrain or headaches after reading or doing close-up work
You may notice these symptoms are worse if you are tired or are in an area with dim lighting.

When to see a doctor
See an eye doctor if blurry close-up vision is keeping you from reading, doing close-up work or enjoying other normal activities. He or she can determine whether you have presbyopia and advise you of your options.

Seek immediate medical care if you:

Have a sudden loss of vision in one eye with or without eye pain
Experience sudden hazy or blurred vision
See flashes of light, black spots or halos around lights
Have double vision
Anatomy of the eye
Anatomy of the eyeOpen pop-up dialog boxEyeballs with point of focus without presbyopia (top) and with presbyopia (bottom)
PresbyopiaOpen pop-up dialog box
To form an image, your eye relies on the cornea and the lens to focus the light reflected from objects. The closer the object, the more the lens flexes.

The cornea is the clear, dome-shaped front surface of your eye.
The lens is a clear structure about the size and shape of an M&M’s candy.
Both of these structures bend (refract) light entering your eye to focus the image on the retina, located on the inside back wall of your eye.
The lens, unlike the cornea, is somewhat flexible and can change shape with the help of a circular muscle that surrounds it. When you look at something at a distance, the circular muscle relaxes. When you look at something nearby, the muscle constricts, allowing the relatively elastic lens to curve and change its focusing power.

Presbyopia is caused by a hardening of the lens of your eye, which occurs with aging. As your lens becomes less flexible, it can no longer change shape to focus on close-up images. As a result, these images appear out of focus.

Risk factors
Certain factors can make you more likely to develop presbyopia, including:

Age. Age is the greatest risk factor for presbyopia. Almost everyone experiences some degree of presbyopia after age 40.
Other medical conditions. Being farsighted or having certain diseases — such as diabetes, multiple sclerosis or cardiovascular diseases — can increase your risk of premature presbyopia, which is presbyopia in people younger than 40.
Drugs. Certain drugs are associated with premature presbyopic symptoms, including antidepressants, antihistamines and diuretics.