Overview Of Presbyopia
Presbyopia is a condition in which the lens of the eye loses its ability to focus. This makes it hard to see objects up close.
Causes Of Presbyopia
The lens of the eye needs to change shape to focus on objects that are close. The ability of the lens to change shape is because of the elasticity of the lens. This elasticity decreases slowly as people age. The result is a slow loss in the ability of the eye to focus on nearby objects.
People most often begin to notice the condition at around age 45, when they realize that they need to hold reading materials farther away in order to focus on them. Presbyopia is a natural part of the aging process and it affects everyone.
Symptoms of presbyopia include:
- Decreased focusing ability for near objects
Exams & Tests
The health care provider will perform a general eye exam. This will include measurements to determine a prescription for glasses or contact lenses.
Tests may include:
- Exam of the retina
- Muscle integrity test
- Refraction test
- Slit-lamp test
- Visual acuity
Treatment Of Presbyopia
There is no cure for presbyopia. In early presbyopia, you may find that holding reading materials farther away or using larger print or more light for reading may be enough. As presbyopia worsens, you will need glasses or contact lenses to read. In some cases, adding bifocals to an existing lens prescription is the best solution. The reading glasses or bifocal prescription will need to be strengthened as you get older and lose more ability to focus up close.
By the age of 65, most of the lens elasticity is lost so that the reading glasses prescription won’t continue to get stronger.
People who do not need glasses for distance vision may only need half glasses or reading glasses.
People who are nearsighted may be able to take off their distance glasses to read.
With the use of contact lenses, some people choose to correct one eye for near vision and one eye for far vision. This is called “monovision.” The technique eliminates the need for bifocals or reading glasses, but it can affect depth perception.
Sometimes, monovision can be produced through laser vision correction. There are also bifocal contact lenses that can correct for both near and far vision in both eyes.
New surgical procedures are being evaluated that can also provide solutions for people who do not want to wear glasses or contacts. Two promising procedures involve implanting a lens or a pinhole membrane in the cornea. These very often can be reversed, if necessary.
There are two new classes of eye drops in development that may be able to help people with presbyopia.
One type makes the pupil smaller, which increases the depth of focus, similar to a pinhole camera. A drawback of these drops is that things appear slightly dimmer. Also, the drops wear off over the course of the day, and you may have a harder time seeing when you go from bright light to dark.
The other type of drops works by softening the natural lens, which becomes inflexible in presbyopia. This allows the lens to change shape as it did when you were younger. The long-term effects of these drops are unknown.
People who are having cataract surgery can choose to have a special type of lens implant that allows them to see clearly in the distance and up close.