AGING EYES
 

The term “presbyopia” comes from the Greek word meaning “old eye”, which accurately describes the condition which affects people over the age of 40. Along with greying hair and stiffening joints, presbyopia is one of the inevitable aspects of the normal aging process. As we get older, our eyes gradually lose the ability to focus clearly up close. When light enters the eye, it passes through the cornea, the pupil and the lens before it reaches the retina at the back of the eye. In younger eyes, the lens is able to quickly and easily change shape to focus the light on the retina, allowing us to focus on objects both near and far. However, the lens becomes less flexible with age, losing its ability to change shape as easily.

SYMPTOMS OF PRESBYOPIA

The gradual deterioration of vision typically begins around the age of 40 but is often noticed only sometime later.

Common symptoms include difficulty seeing close objects, eye fatigue or headaches after doing close work, needing brighter lighting when reading or doing close work, blurred vision at normal reading distance and needing to hold reading material at an arm’s distance to focus properly.

Even if you are not experiencing symptoms, it is advisable to have an eye examination by the age of 40 to check on your visual health.

It is possible to have presbyopia in addition to or in combination with other types of vision problems, such as shortsightedness, farsightedness or astigmatism.

Farsightedness, hyperopia, is sometimes confused with presbyopia because in both conditions distant objects are clear while closer objects appear blurred.

However, hyperopia is a refractive error that is present at birth, while presbyopia is part of the aging process.

RISK FACTORS FOR PRESBYOPIA

Most people will develop presbyopia at some stage, usually between the ages of 40 and 65.

Eye trauma or surgery, as well as certain medical conditions or medications can increase the risk of younger people developing premature presbyopia earlier than the usual age of onset.

These medical conditions include cardiovascular disease, diabetes and certain neurological disorders.

Medications such as antidepressants, antihistamines and diuretics can cause presbyopia to develop earlier than usual.

TREATMENT OF PRESBYOPIA

If presbyopia is undiagnosed or uncorrected, vision is likely to deteriorate gradually and will increasingly affect a person’s productivity, lifestyle and everyday activities. There are several treatment options available. A discussion with your optometrist will guide you towards making the most appropriate choice for your specific visual needs.

Prescription lenses are necessary if there is a vision problem over and above presbyopia. Depending on the problem and your particular lifestyle and preferences, there a number of options.

Bifocals have two different types of focus in one lens, the upper part for distance vision and the lower section for close work, with a line between them which may or may not be visible.

Trifocals have three lens areas to correct for close-up, mid-range and far vision.

Progressive lenses are similar to bifocals but have a gradual or blended transition between the two prescriptions instead of separate sections.

Over-the counter reading glasses may work well to assist with reading and close work for very short periods. When selecting a pair of over-the-counter reading glasses, try different degrees of magnification and choose the lowest magnification that allows you to read a newspaper comfortably. Ideally, the specific power of the reading glasses should be determined by an eye examination, particularly as the strength of the lenses may not be the same for both eyes which could lead to eyestrain.

For those who prefer to wear contact lenses rather than glasses there are three options available.

As with bifocal glasses, bifocal contact lenses have two prescriptions in one lens, the upper portion for distance vision and the lower for close work.

Multifocal contact lenses have several zones set for different powers.

With monovision contact lenses one eye is corrected for distance vision and the other for close-up vision; the brain learns to automatically adjust to the required focus.

There are various surgical procedures to correct presbyopia, including changing the curvature of the cornea, creating monovision and replacing the natural lens with a synthetic lens. Your optometrist will refer you to an ophthalmologist if you are interested in exploring these options.

Prescription eye drops for presbyopia reduce the size of the pupils so that the eyes are able to adjust focus and improve near vision.

They are effective for up to six hours, but some side effects may occur.

Because of the natural progression of aging, your vision may change, and it may become necessary to adjust your prescription. Visit your optometrist regularly to monitor your vision and your visual health. Certain eye conditions develop gradually without symptoms until the later stages.

By examining your eyes regularly, your optometrist will be able to detect signs of eye disease before you become aware of symptoms and irreversible damage has occurred.