Most people start to have problems with their vision as they get older. One area where you can have a problem is with contrast sensitivity, which is what allows you to see the edges of objects. If you don't think this is important, try going up and down stairs when you can't tell where the edge of each step is. Loss of contrast sensitivity can contribute to an increased risk of falls in the elderly.
A new study has found that contrast sensitivity can be improved with exercises that help train your brain. Researchers at the University of California, Riverside, had a group of both older and younger individuals go through five sessions of behavioral exercises. Before the training, their vision was tested.
In each hour-and-a-half long session, the participants watched 750 striped patterns that were shown quickly on a computer screen. Each image had an amount of visual "noise," which was like snow on a television screen. The participants were asked whether each image was rotating clockwise or counterclockwise. Every time they answered correctly, they heard a beep. Essentially, the sessions were training the brain to ignore distractions like the visual noise.
After the five sessions of training, older participants had improved in their ability to see edges. They also did better at making out letters on an eye chart held at reading distance, but not on a chart at the standard distance.
Younger participants also improved their contrast sensitivity, but not as much as the older participants improved. This is probably because their eyesight was better to begin with and there was less room for improvement.
The participants were able to improve their vision because contrast sensitivity is processed in the visual cortex of the brain and is not a factor of the optics of the eye. The findings suggest that the visual cortex of the brain can be strengthened.
An earlier study with older individuals who received contract sensitivity training found that the improvement lasts at least three months.