Exercise To Keep Your Eyes Healthy

Everyone knows that keeping fit will help you to grow old gracefully and may slow the degenerative processes associated with ageing – but did you know that it can also keep your eyes healthy?  It’s true; recent research has shown that taking regular exercise can slow the progress of macular degeneration, an age-related condition that affects the back of the eye.

Improving Macular Degeneration

Macular degeneration can cause distorted vision or blank spots, and it is most common in those over the age of 50. Researchers at Emory University in Atlanta and at the Atlanta Veterans Administration Medical Centre have shown that regular exercise can actually help the fight against the condition – at least in mice.

They were inspired by previous research that showed regular exercise can increase substances known as growth factors in animals’ brains.  One particular substance of interest was brain-derived neurotrophic factor, or BDNF.  If regular exercise can help keep the neurons in the brain healthy, it stood to reason that it can also help keep the neurons in the eye healthy, and so the team at Emory University studied the effects in mice.

The Experiment


The researchers took two groups of mice – one group remained sedentary, whilst the others ran at a gentle pace on tiny treadmills, for one hour per day.  After two weeks, half of the mice in each group were exposed to painfully bright lights for four hours, whilst the remaining mice remained in dimly lit cages – this is a commonly used technique for testing retinal damage in animals (as it is comparable to the slow neuron loss experienced by humans).  The mice then returned to their original routines for a further two weeks, before being tested for neuron levels.

The unexercised, sedentary mice that had been exposed to the light showed signs of severe retinal degeneration, having around 75% less neurons than the sedentary mice who had remained in the cages.  Those mice which were exposed to the light but had exercised, however, had twice as many functioning neurons than the sedentary mice.  What’s more, the remaining cells were much more responsive to normal light, suggesting that exercise had indeed benefited them.

In an additional study, the researchers tested another two groups of mice – one sedentary and one exercising – for levels of BDNF in the blood stream and in the eyes, after two weeks of their routines.  The runners showed significantly higher levels of BDNF than the non-runners.  What’s interesting is that when injected with BDNF-blocking chemicals, the runners’ eyes deteriorated just as badly when exposed to bright light as those who had remained sedentary.

This study, as mentioned, is not conclusive proof of the benefits of exercise in humans, but it’s certainly an interesting piece of research. Only time and further studies can uncover the true benefit of exercise for human eyes – but, in the meantime, taking up running or a little regular exercise couldn’t possibly be a bad thing!