Philosophers have wondered for centuries whether someone who was blind from birth would “see” the world in the same way as people with normal vision. After all, there’s much more to perceiving the world than properly functioning eyes. Think of it: otherwise all you’d need to do is strap a camcorder to a car and you’d never have to learn how to drive!

But there are surprisingly few cases of people who were born completely blind and then had their sight restored after many years of blindness. If a patient can be cured, it’s usually done quite early in life. But a few cases have emerged in recent years, the most promising of which was a woman from India who goes by the initials S.R.D. She was born almost completely blind, able to tell day from night but otherwise unable to perceive anything visually. At the age of 12, she underwent surgery to correct her vision, which was successful in one eye. Almost overnight she was able to experience a whole new visual world, and she has had vision that was correctable to near-normal for the past 20 years.

Although researchers weren’t aware of S.R.D.’s case until recently, her mother told a team led by Yuri Ostrovsky that it took several months for her daughter to be able to recognize basic objects and navigate the world using sight. Eventually she completed seven years of school, married, and now works as a maid. She can get around her town by herself and walks without a cane.

But what Ostrovsky’s team wanted to know was whether S.R.D.’s visual system was truly normal. Using a laptop computer, they gave her ten different tests of the visual system, including visual memory, shape matching, depth perception, face/nonface discrimination, face identification, and gaze estimation. They gave the same test to another woman from India who had accurate vision and the same education level and social status. They also tested several Americans with similar visual acuity to S.R.D. (about 20/200).

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