(Image: Paul Blow)
In his 1920 book , William Bates claimed that doctors did not understand how the eye works and that anyone could achieve perfect vision by, for example, staring at the sun (do not try this at home!). His : countless books and websites still claim that “natural vision correction” can be achieved simply by doing eye exercises.
In fact, there is no evidence that any kind of exercise improves the eye’s focusing powers, which is the cause of most vision problems. But there is evidence that the brain can get better at interpreting the signals it receives from the eyes. The main focus of research has been contrast sensitivity – how well we can discern things that are only slightly darker or lighter than their surroundings. It is important for reading in poor light, say, or driving at night.
Advertisement
There have been some apparently impressive results reported with training schemes involving Gabor patches. These look like blurry lines, and the exercises typically involve spotting ever-fuzzier lines that get harder and harder to distinguish from the background. , who tend to have worse contrast sensitivity, could regain similar abilities to those in their early 20s.
Several apps are now on sale so you can try these exercises at home, but or just make people better at detecting Gabor patches. Most eyesight specialists want to see more controlled trials done before they recommend their use. “It’s probably too soon to know,” says , an ophthalmologist at Yale University.
(Image: Gene Blevins/Reuters/Corbis)
In the meantime, some of the strongest evidence that brain training can improve vision comes from studies of computer gamers. , a neuroscientist now at the University of Geneva, Switzerland, first became aware of the effect after some students who were keen gamers scored more highly than expected on vision tests.
“Students who were keen gamers scored better than expected on vision tests”
Her team has been studying this phenomenon ever since. They have shown that people who spend a lot of time playing action games have better contrast sensitivity than non-players. Not only that, but when they asked people who don’t usually play these games to do so for 6 hours a week for nine weeks, by 43 per cent.
The effect is strongest with so-called first-person shooters, which some claim increase violent behaviour. “It’s the games that are ostracised,” says Bavelier. For comparison, non-gamers who played The Sims for six weeks only improved by 11 per cent. However, it might be possible to create games that have the same effect as first-person shooters without the violence.
The people in her study were all in their 20s and already had good vision, so Bavelier doubts they would notice the effect on their vision in everyday life. Some of her volunteers spotted one result of the training, though: the screens of old-style cathode-ray tube monitors seemed to start flickering because their vision was now sharp enough to spot the pixels being refreshed. Fortunately, that side effect doesn’t happen with modern LCD screens.
Bavelier thinks that computer-game-based brain training is most likely to produce meaningful improvements in vision in people who already have problems, although her team has yet to demonstrate this. In theory, older people with declining contrast sensitivity stand to benefit most. The trouble is that most action video games are too fast for older adults, Bavelier says, but some researchers are creating games .
Brain training is also showing great promise as a treatment for what’s called lazy eye, where the brain ignores the input from one eye, often because of a squint in childhood. It affects about 3 per cent of the population.
The standard treatment is to put a patch over the good eye to force the brain to use the bad one, but children sometimes refuse to cooperate, leading to permanent vision problems. The brain-training approach involves playing the computer game Tetris through special goggles, so that one eye just sees the falling blocks and the other sees the shapes at the bottom of the screen they slot into. The game can be played only if the brain uses both eyes, working together.
In one study, after 10 hours of training, , equivalent to 2 or 3 lines on an eye chart. The biggest surprise was that adults were able to benefit at all, as patching does not work in children over 12, says , an ophthalmologist at McGill University in Montreal, Canada, who led the work. “There’s no current treatment for adults,” he says.
A , called Dig Rush, is now being developed for home use. It uses cheap 3D glasses to show different images to each eye.
Read more: “Good looking: 6 surprising ways to improve your eyesight“
This article appeared in print under the headline “Game on”
