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fork(2) [soylentnews.org] writes:

      Researchers at Vanderbilt University have found that stimulating the visual cortex of the brain for 20 minutes with a mild electrical current can improve vision for about two hours, and those with worse vision see the most improvement, according to a paper published this week in Current Biology and summarized here [sciencedaily.com] in ScienceDaily.

"It's actually a very simple idea," said co-author Geoff Woodman, associate professor of psychology. "This kind of stimulation can improve cognitive processing in other brain areas, so if we stimulate the visual system, could we improve processing? Could we make someone's vision better -- not at the level of the eye, like Lasik or glasses, but directly at the level of the brain?"

      Twenty young, healthy subjects with normal or near-normal vision were asked to evaluate the relative position of two identical vertical lines and judged whether they were perfectly aligned or offset. The test is more sensitive than a standard eye chart, and gave the researchers are very precise measurement of each subjects' visual acuity.

      The researchers then passed a very mild electric current through the area at the back of the brain that processes visual information. After 20 minutes, the subjects were asked to perform the test again, and about 75 percent showed measurable improvement following the brain stimulation.

      [...]

      They also measured how the stimulus changed the speed with which the brain processed visual information and whether the stimulation also improved the subjects' contrast sensitivity -- their ability to differentiate between multiple shades of gray.

      The contrast experiment was notable because they found that the stimulation only improved contrast sensitivity at frequencies also associated with visual acuity, indicating that it was just the subjects' visual acuity that was being affected, not the contrast sensitivity.

      Robert Reinhart, one of the authors of the paper, said, "Now we have a new tool that could be valuable for researchers investigating fundamental questions about how the visual system works."

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