Presbyopia (>pres-be-O-pe-ah) is a vision condition caused by the aging of the eye. It affects nearly everyone by the age of 50. The Crystalline lens of the eye thickens throughout life making it harder and less flexible over time. The progressive loss of elasticity of the lens results in the eye becoming less capable of focusing on close objects. Tasks like reading small print and computer work become more difficult. Distance vision however is usually unaffected.
Presbyopia might seem to occur suddenly but the actual loss of flexibility transpires over a number of years. It typically becomes noticeable in the early to mid-forties as it is a natural part of the aging process of the eye. It is not a disease and is not preventable but once diagnosed treatment can relieve eyestrain and improve near vision clarity. The visual effects caused by presbyopia can slowly worsen for several years but will stabilize between the ages of 65 and 70.
When people develop presbyopia they have the tendency to hold reading material at arm’s length to focus properly. Other symptoms include:
- Headaches or eye strain when performing near work
- Blurred vision at normal reading distances
- Needing brighter lights to see clearly
If you are under the age of 40 and notice difficulty reading uncorrected hyperopia (farsightedness) may be the cause. This is easily corrected with contact lenses or eyeglasses.
To help compensate for presbyopia your eye care practitioner may prescribe reading glasses bifocals trifocals multifocals or contact lenses. Presbyopia is completely treatable with these forms of corrective eyewear. New research into surgical procedures for presbyopia may prove successful in the coming years.
Since presbyopia can complicate other common vision conditions like hyperopia myopia and astigmatism your optometrist will prescribe specific lenses to achieve clear vision. Eyewear might only be necessary for close work such as reading or it might be best to wear it at all times. Since the effects of presbyopia continue to change the ability of the lens to focus properly stronger prescriptions might be necessary to maintain clear vision.
Glasses with bifocal trifocal or progressive addition lenses (PALs) are the most common method of correction for presbyopia. Advances in progressive lens materials have allowed companies to produce thin lightweight lenses without the distinctive line separating the visual fields. These provide wearers with a gradual change in prescription strength between distance and near vision. They have a clear ‘corridor’ where objects at an intermediate distance are in focus thereby avoiding a sharp image transition when the eyes move from one distance zone to another.
Reading glasses are another option. These are ideal for people who only have difficulty seeing printed matter. Reading glasses are solely for close work. Some people choose to wear them over top of contact lenses that are prescribed for distance vision. They are available in a wide range of lightweight attractive designs. Inexpensive reading glasses are readily available over-the-counter at retail stores but prescription reading glasses from your eyecare provider will ensure balanced vision between the two eyes exact fitting reduced distortion and precise optics.
Multifocal contact lens technology has advanced considerably providing wearers with new levels of choice and comfort. These are available in either soft or rigid gas permeable materials. They offer the convenience of contact lenses with the ability to have clear distance intermediate and near vision. The popularity of these contact lens designs has resulted in numerous offerings from most major contact lens companies.
Another option for contact lens wearers who are just starting to have the early symptoms of presbyopia is called Monovision. This fitting technique results in one eye wearing a contact lens for distance vision and the other eye for near vision. After a period of adjustment to the different images received from each eye the brain starts to favour one eye or the other depending on the task. Most people see reasonably well but there are limitations to this approach namely lack of depth perception.