Everything in your body changes as you get older ... as you well know, if you are over the age of 14! Some of the changes are purely aesthetic - your wrinkles and grey hair may or may not bother you. Some of the changes, however, are functional - such as a loss of eyesight flexibility. The natural contraction of the lens in our eye, and resulting difficulty in focusing on close items, is called presbyopia, and is a normal part of aging. Today we run through the signs and symptoms of presbyopia, and how you can correct it with reading glasses.
What is Presbyopia?
Presbyopia has the same symptoms as farsightedness (the opposite of nearsightedness), but a far different cause. Presbyopia occurs when the lens loses flexibility due to aging, and is an ordinary part of life for many people over 40.
Presbyopia can be thought of as a loss of ability to focus on things at all different distances; the condition makes your eyes like a 'fixed focus' camera rather than an 'auto-focus' one. For things that are moving, or less than 6 feet away, it can be difficult to get good pictures. Reading is difficult and tiring for the eyes.
Diagnosing Presbyopia
Presbyopia is often diagnosed symptomatically - that is, an ophthalmologist will perform an eye exam and determine when you can see items clearly and when you can’t. They'll also give you a prescription for reading glasses, or an idea of which generic reading glasses you can use (often much better value!). Your doctor will usually give you eyedrops to dilate your pupils and make it easier to see to the back of your eye. They will then look into your eye using an opthalmoscope, a device with both a magnifying glass and a light attached.
Options for treating presbyopia
These are the same as for treating most other vision dysfunctions - you can either wear reading glasses or general corrective glasses, or contact lenses. Here are the most common solutions for presbyopia:
- Ordinary reading glasses - these are used especially when the person's vision for things other than near-tasks is otherwise good
- Progressive addition lenses, or bifocals - if there is an existing vision problem to correct (like astigmatism or nearsightedness) in addition to the presbyopia, bifocals may be recommended rather than magnifying reading glasses. Progressive addition lenses are similar to bifocals, but with a more gradual distinction between the two prescriptions.
- Contact lenses can also be used to treat presbyopia, including he more comfortable gas-permeable contact lenses
- Surgery is an option - it is called conductive keratoplasty. It is not available in all countries, however.
Experimental treatments
The laser surgery that many people have for near sightedness is not suitable for presbyopia, since the cause of the defect is so radically different. There are trials underway to try to modify LASIK for presbyopia, but they are in their early stages.
Another highly experimental treatment involves injecting an elastic gel into the eyeball to take the place of the hardening lens. Scientists have little idea of the long term effects of this treatment, though.
If you are likely to undergo cataract surgery in the near future, you may be able to have presbyopia-correcting intraocular lenses transplanted, and achieve clear vision at any distance. However, doctors will not perform this surgery for ordinary cases of presbyopia.
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