Studies have shown that exercise can slow down and even prevent common causes of vision loss. But what type of workout is good for your eyes?
Before we begin, we need to understand the basics of choroidal neovascularization (CNV). According to medscape.com:
Choroidal neovascularization describes the growth of new blood vessels that originate from the choroid through a break in the Bruch membrane into the subretinal pigment epithelium (sub-RPE) or subretinal space.
CNV basically means that there's a harmful overgrowth of blood vessels in the eyes. Symptoms include:
Colors losing their brightness
Colors appearing differently in each eye
Loss of vision without pain
Sizes of objects appearing differently in each eye
Flashes of light or flickering occurring in your central vision
So, you can understand why researchers at the University of Virginia School of Medicine were pretty excited when they discovered that exercise can reduce this issue by up to 45 percent ... in mice, anyway.
The paper, Voluntary Exercise Suppresses Choroidal Neovascularization in Mice, is the first experimental evidence that shows exercise can reduce the severity of macular degeneration, a leading cause of vision loss.
Research shows that exercise can reduce the severity of macular degeneration, a leading cause of vision loss.
Researcher Bradley Gelfand, Ph.D., told Science Daily:
There has long been a question about whether maintaining a healthy lifestyle can delay or prevent the development of macular degeneration. The way that question has historically been answered has been by taking surveys of people, asking them what they are eating and how much exercise they are performing ... The problem with that is that people are notoriously bad self-reporters ... and that can lead to conclusions that may or not be true. This [study] offers hard evidence from the lab for the very first time.
To determine the effectiveness of exercise on CNV, two tests were done. One test, which compared mice that voluntarily exercised versus those that did not, found that exercise reduced the blood vessel overgrowth by 45 percent. Then, a second test was done to confirm the findings. It found a reduction of 32 percent.
During the study, age-matched wild-type mice were housed in cages that were equipped with or without the mouse equivalent of a treadmill. After four weeks of voluntary running or not running, depending on which cage the mice were allocated to, the mice were subjected to “laser injury to induce CNV.”
After they recovered from the surgery, the mice were placed back in cages with or without exercise wheels for another seven days. Then CNV lesion volumes were measured by confocal microscopy. The results were tallied and the clear winners were the mice who lived in a cage with a running wheel.
What type of exercise?
The researchers found that both the intensity and the duration of the exercise didn’t have to be high. To receive the benefits from exercise, the mice didn’t have to crush the mousey equivalent of a CrossFit WAD or train for a fuzzy marathon. And, even cooler, more exercise didn't mean more benefit.
In fact, researcher Bradley Gelfand was said, "As long as they had a wheel and ran on it, there was a benefit."
So, I hate to sound like a broken record but I think this is yet another win for our good friend walking. It does appear that making it more of a brisk walk would be advantageous, but there's no need to break into a run or to do it for hours and hours per week. (Unless, of course, you want to.)
How it works
Now, you may be wondering “How on earth does this work, Brock?”
Well, I don’t know. And even the scientists who did the research aren't certain how exercise is preventing the blood vessel overgrowth. They speculate that there could be a variety of factors at play, including increased blood flow to the eyes, which is a mechanism of action that's been linked to the cognitive benefits of exercise as well. So, raising your heart rate seems to be good for your eyes, brain, and cardiovascular system!
The researchers also brought up an interesting chicken and egg scenario. They noted that the onset of vision loss (in mice and humans) is often associated with a decrease in exercise. As a person’s eyes and vision deteriorate, they tend to engage in less physical activity. So, it can be challenging to know exactly which event is causing the other. But whether the vision loss is making a person exercise less or getting less exercise is kicking off the vision loss, it's clear that there is a correlation, and the prescription is: exercise.
This isn’t the only study to show the promising interplay between vision and exercise either. Several studies have found a link between regular physical exercise and a reduction in the risk of issues like cataracts, glaucoma, and macular degeneration.
Even if your exercise program is not directly improving your eyesight, it certainly has an effect on other health issues like diabetes (which can damage the blood vessels of the retina) and high blood pressure (which can lead to high ocular pressure and glaucoma).
According to yoursightmatters.com, exercise can help these common eye conditions.
Running or walking can help decrease the risk of age-related cataracts
Exercising three or more times per week will make you less likely to develop wet age-related macular degeneration
Moderate intensity, low-impact exercise helped significantly reduce eye pressure in young adults with glaucoma
Exercises for your eyes
Years ago, I read the book The Art of Seeing by Aldous Huxley, which is a handbook that chronicles Huxley’s victory over his own near-blindness and details the simple eye exercises that anyone can follow to improve eyesight.
The book was not well received by the ophthalmological field, but it did resonate with me. So much so that years later, when websites like The Vision Gym started popping up, I was all over them. And even though my own optometrist isn’t 100 percent taken with the idea of me putting off wearing glasses in favor of keeping my own eye muscles strong, there is some evidence that not only exercising your body (as in the previous study) but also directly exercising your eyes can be helpful.
Here are a few eye exercises I do that you can also try:
- Hold a pen a few centimeters away from your eyes and focus on the pen.
- Slowly move the pen away from your face while maintaining your focus on the pen.
- Stop focusing on the pen and look away for 20 seconds (preferably as far away as you can).
- Then focus back on your pen and slowly bring it back toward your eyes.
- Look far away again for 20 seconds.
- Repeat three times.
- Find a spot on the floor about three meters (10 feet) in front of you and focus on it.
- Then, start to repeatedly trace an imaginary figure eight on the floor with your eyes for 30 seconds.
- After 30 seconds, switch directions, and trace the figure eight for another 30 seconds.
- Try not to let your eyes go out of focus as you go. Make sure you see the marks, bumps, and scratches on the floor.
Near and Far
- Hold your good ol' pen about 25 centimeters (10 inches) from your face and focus on it for 15 seconds.
- Find an object roughly 4 meters away (15 feet) and focus on it for 15 seconds.
- Return your focus to your pen.
- Repeat five times.
This is a pretty popular technique for alleviating eye strain when working on a computer. My buddy Katy Bowman, a biomechanist, introduced it to me.
Simply set a timer to go off every 20 minutes. When it goes off, look at something 20 feet away for 20 seconds. That’s all. 20-20-20, get it?
Katy has her own eye helper as well, this is what she does:
University of Virginia School of Medicine researcher Bradley Gelfand told Science Daily his secret motivation for doing the CNV research on those mice we talked about earlier was "... sort of selfish. I was hoping to find some reason not to exercise. It turned out exercise really is good for you."
Well said, doc. Exercise really is good for you!