That's because the brain recruits cells normally devoted to hearing to help them see better, the research revealed.

"The brain is very efficient and it's not going to let this huge territory that is the auditory cortex and all the processing that it has go to waste," said study leader Stephen Lomber of Canada's University of Western Ontario. The auditory cortex is the part of the brain that controls hearing.

"So it makes sense that other senses will come in and colonize."

In behavioral tests, Lomber and his team determined that domestic cats born deaf have better peripheral vision and motion-detection abilities than cats born with normal hearing—a finding that parallels visual test results