What Causes Presbyopia?
Presbyopia, also known as the "short-arm syndrome" is a normal part of the eye's aging process
that causes near vision to become difficult. Onset is usually between the ages of 40 and 50
and it affects the majority of people. The name presbyopia comes from the Greek word presbus,
meaning old man. In young people, the lens of the eye is soft and flexible. The most commonly
accepted explanation for presbyopia is that a gradual hardening of the lens takes place over
time. Hardening of the lens is thought to reduce its ability to change shape and bring near
objects into focus. Presbyopia is often confused with "farsightedness" (hyperopia), which is a
term used to describe how the eye focuses distant objects, when the eye's focusing system is
in a relaxed state.
Presbyopia Symptoms and Signs
- Difficulty seeing clearly for close work
- Print seems to have less contrast
- Brighter, more direct light required for reading
- Reading material must be held further away
- Fatigue and eyestrain when reading
Presbyopia Treatment - Eyewear
Traditionally, bi-focal glasses were prescribed to compensate for presbyopia with the bottom
section of the lenses used for close work. Benjamin Franklin invented bifocals to avoid
having to carry a pair of glasses for distance and a second pair for reading. Today,
many patients choose "Progressive Addition Lenses" (PALs), which provide vision correction
for all distances. Progressive lenses do not have the "dividing line" visible in traditional
bifocals.
Reading glasses are another choice. Unlike bifocals and PALs, which are usually worn all day, reading glasses are typically worn just during reading and close work. If you wear contact lenses, your eye doctor can prescribe reading glasses that you can wear over your contact lenses.
There are also contact lenses for presbyopes called "multifocal" contact lenses. They are available in both gas permeable or soft lens materials. Another type of contact lens correction for presbyopia is monovision, in which one eye wears a distance contact lens and the other wears a contact lens for near vision. While some people are delighted with this solution, others complain of dizziness, nausea or reduction in their depth perception.
In Summary
Presbyopia is a normal part of the aging process. Today, there are a number of treatments available. The specific treatment chosen should take into account the individual's age, lifestyle, occupation and hobbies. Your eye doctor is the best one to recommend which solution is appropriate for you and your particular vision needs.
