Losing focus with the years

by Dr Mark Donaldson, Eye Doctors

As you get older (40 plus), the ability to see well up close is gradually lost, glasses are required and as the years pass even long distance vision isn’t so good without glasses. So what is happening?

In youth, the eye changes its focus for near and far automatically. It does this by adjusting the power of the lens. Each eye has a lens, which is found directly behind the pupil of the eye. The lens is for focusing light on the centre of the retina.

So the eye changes the focus by adjusting the shape of the lens. The youthful lens is perfectly clear.

As you age, the lens gradually stiffens and its ability to change focus is lost. That’s where reading glasses come in.
Unable any longer to increase the power of your own lens, you have to add that power by putting lenses in front of your eyes.

As people enter their sixties and seventies, the fibers of the lens start to lose their transparency and block the light.
Initially, you notice that things don’t look as clear as they did even with new glasses. You may also notice glare and gradually sight may be totally lost. This is what is called a cataract – an opaque lens.

Why does the lens stiffen with age and eventually lose its transparency? It is because the proteins in the fibres of the lens are degraded by oxidation.

Despite many anti-oxidant measures deployed by the lens these are eventually overwhelmed by the ravages of time and by the age of 70 all people have lost the ability to focus naturally and the majority have identifiable early cataract present, even if it isn’t causing them a problem with their sight.

To keep your eyes in good health, I recommend wearing a hat and a good pair of sunglasses especially in the summer. Eat nourishing food and avoid cigarette smoke.

If you have concerns about your sight, see your local optometrist. The expertise and equipment required to provide sight-restoring cataract surgery is available in Warkworth at the Rodney Surgical Centre. I performed the first cataract operation when the centre opened in 2010 and I have operated on hundreds of patients since then.