Could Exercise Help to Protect Our Eyes as Get Older?

Most people are lucky enough to use their eyes constantly, every waking hour. They allow us to see the smiles of our loved ones, complete the work that is required of us, and enjoy the world in all its glory. Yet, taking the gift of sight for granted is surprisingly easy.

The chances are, you can’t remember the last time you thought about the incredible gift that is your vision. It is likely even longer since you considered what you can do to ensure you cherish it.

The fact is, most of us are all too aware of the importance of exercise for our physical and mental health. Many of us pay for expensive gym memberships, attend fitness classes with friends, or simply choose to walk to our destination rather than take the car now and then. But while we may be doing all these things to keep fit generally, we rarely consider the benefits of exercising for our eyes.

However, growing evidence indicates that exercise could actually play a major role in keeping our eyes healthy – particularly when it comes to the risk of macular degeneration.

What is Macular Degeneration?

Also called age-related macular degeneration (AMD) due to its increased prevalence as we get older, macular degeneration is a condition that affects the macula – an area at the back of the eye. The macula is the central area of the retina. It is responsible for processing what we see in our central vision and allows us to make out fine details – both up close and at a distance.

AMD develops when age-related damage begins to affect the macula. This affects our vision, potentially causing blurred vision, dark spots in the central vision, distortion, blind spots, and as the condition worsens, the complete loss of central vision.

Improving Macular Degeneration

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.

The researchers were inspired by earlier research that showed how regular exercise can increase substances known as growth factors in the brains of animals. Of particular interest was a substance called brain-derived neurotrophic factor (BDNF). They theorised that, if regular exercise can help keep the neurons in the brain healthy, then perhaps it can also keep the neurons in the eyes healthy. So, they decided to put this theory to the test.

The Experiment

Two groups of mice helped them to prove their hypothesis. One group remained sedentary while the mice in the other group ran at a gentle pace on treadmills for one hour per day. After two weeks, half of the mice in each group were exposed to bright lights for four hours while the other half remained in dimly lit cages. This technique is commonly used to test for retinal damage in animals, as it simulates the slow neuron loss experienced by humans. The mice were then returned to their original routines for a further two weeks before being tested for neuron levels.

As expected, the sedentary mice that had been exposed to the light showed signs of severe retinal degeneration, having around 75% fewer neurons than their fellow mice who remained in the cages. Amazingly, the exercised mice that were exposed to the light maintained twice the number of neurons as the sedentary mice. Moreover, the remaining cells were more responsive to normal light, suggesting that exercise had improved their overall function.

In a further study, the researchers tested another two groups sedentary vs active mice. The mice were tested for levels of BDNF in the bloodstream and in the eyes, following two weeks of their assigned routines. The active mice once again came out on top. They showed significantly higher levels of BDNF than their inactive counterparts.

Furthermore, when injected with BDNF-blocking chemicals, the active mice’s eyes deteriorated just as badly as when they were exposed to bright light, indicating the role of BDNF in maintaining healthy neurons.

Could Exercise Help in Humans?

Of course, mice are much different to humans and studies such as this are simply a starting point for learning more about our own bodies. But while these findings may not be conclusive proof of the benefits of exercise for human eyes, it does give you something to think about!

The findings of this study were further supported by another study, published in 2020, by researchers from the University of Virginia School of Medicine. They found that exercise reduced the harmful overgrowth of blood vessels in the eyes of lab mice by up to 45% – a key contributor to macular degeneration and several other eye diseases!

Only time and further studies can confirm the true benefits of exercise for our eyes and vision. But in the meantime, taking up a little more exercise couldn’t possibly be a bad thing!

If you have any questions about your eye health or would like to Book a Consultation to learn more about our treatments, get in touch with one of our friendly clinic coordinators today. We’re always happy to help!