Vision through the generations

Do blurred words suddenly snap back into focus when you hold your book at arms length?

If they do you could be showing the first signs of presbyopia.

What is presbyopia?

The lens gradually begins to stiffen from about the age of ten, but it isn't until we reach our early-to-mid-forties that most of us begin to notice the first signs of presbyopia.

Presbyopia, a name derived from Greek words meaning 'old eyes', is a natural part of the ageing process. The crystalline lens in the eye loses its flexibility as we grow older, making it more and more difficult to focus on close objects.

Our ability to 'see' starts when light enters the eye through the cornea. The shape of the cornea and crystalline lens help refract (bend) the light so that it projects a sharply focused image on the retina.

Over time the lens becomes stiffer hindering its ability to bend and flatten the light. As a result the eye has difficulty focusing on near objects and adjusting quickly to rapid changes in focus on near and distant objects.

The decline in your ability to change focus is gradual - but inevitable.

Common Symptoms of Presbyopia

More than 25 million people in the UK are affected by presbyopia. Common symptoms of the condition include:

• Eye fatigue when doing close work such as sewing, drawing and painting or looking at a computer screen
• Difficulty seeing clearly close up
• Less contrast when reading print
• A need for brighter and more direct light when reading
• Headaches when doing work that requires near vision

Diagnosis and Treatment of Presbyopia

An eye examination that tests your near vision is all that is required for your optometrist to diagnose presbyopia.

If you have no other vision problems, such as myopia (short-sightedness) or hyperopia (long-sightedness), you may only need to wear reading glasses.

Reading glasses will help to refract the light more effectively to compensate for your loss of near vision, making reading at normal range and other close viewing tasks clearer and more comfortable.

Alternatively, you can wear progressive lenses or bifocal spectacles, which combine your presbyopia prescription lens with a plano (or clear) lens to help you view both close and far distances without having to take your reading glasses on and off.

However, if you already wear glasses or contact lenses for another optical condition your optometrist will prescribe bifocal or progressive lenses. Or, you have the option of two separate pairs of glasses, one for near vision and one to correct your existing optical error.

What are progressive lenses?

Progressive lenses provide clear vision not just for near or far, but also for all distances in between without any abrupt changes or visible lines in the lens. Helping you to look good and see well.

The lenses are deigned to give a steady increase in power from the distance vision at the top of the lens - which allows you to clearly see anything that is more than a couple of feet away, to as far as your eyes can see - to reading vision at the bottom of the lens.

Clear near vision will allow you to read comfortably in a natural posture - so no more stretching your arms out as far as you can reach just to read your shopping list or newspaper.

The latest generation of progressive lenses incorporate a wide range of frames, allowing you to keep your own personal style, which means you won't have to wear the large frames typically associated with eye-care. You also have a number of contact lens options including: bifocal contacts, mono-vision lenses (where one contact lens corrects near vision and the other corrects distance vision) or you can wear your normal contacts with reading spectacles.

Will I require frequent lens changes?

Presbyopia gradually affects your vision over a number of years so your prescription will need to be

updated periodically to maintain clear and comfortable vision. However, there should be no need to change your normal eye health regime. Unless otherwise advised your optometrist will review your prescription when you visit him or her for your regular eye examination.

The Eyecare Trust advises that everyone should have an eye examination at least once every two years.