Man blind for 40 years tells of struggle to adapt

A man who regained his sight after 40 years of blindness has told scientists about the extraordinary sensation of being able to see once again.

A man who regained his sight after 40 years of blindness has told scientists about the extraordinary sensation of being able to see once again.

Michael May, an American businessman aged 43, went blind when he was three, but sight to his right eye was restored after a pioneering stem-cell transplant in 2000. Tests and investigations using a brain scanner have shown that while Mr May can see colours and shapes, he still has difficulty understanding the visual world around him.

For instance, Mr May was a good downhill skier - following the verbal instructions of a guide - but now he finds it difficult to ski with his eyes open. He also has difficulty recognising faces, and still cannot recognise his wife by her face alone.

"The difference today and two years ago is that I can better guess at what I am seeing. What is the same is that I am still guessing," Mr May said. "A day doesn't go by that I don't appreciate the visual details around me. I have been building my visual catalogue of these details and although this catalogue is significantly more filled out than it was two years ago, there seems to be an infinite number of visuals to absorb," he said.

Cases of restored eyesight are extremely rare and Mr May's recovery is one of the most studied examples of the phenomenon, said Ione Fine of the University of California at San Diego, who led the study published in the journal Nature Neuroscience.

"He's the first case I know of where sight was transformed from bare light perception to very good optical acuity after such a long period of blindness," Dr Fine said.

Even though Mr May can now see, he cannot interpret the world, which he sees in terms of abstract shapes and colours rather than the recognisable objects and familiar faces that most people instantly recognise and take for granted. "What we knew going into this research was that people who regained their sight later in life, after decades of blindness, seemingly experience more difficulties in adapting to and functioning in the visual world than those individuals who lost and regained their sight later in life," Dr Fine said.

The research on Mr May suggests that the ability to cope with motion and to recognise complex shapes such as faces develops later in childhood. The ability may also be "hardwired" in the brain, which makes it difficult to learn when someone is older.

Mr May had to close his eyes while skiing because the sense of moving unsettled him. "I think the sensation of motion overwhelmed him at first, it took him a while to process the sensations of looming so he didn't feel he was going to collide," Dr Fine added.

After two years of practising, however, Mr May can now ski with his eyes open, and has begun to use the patterns of light and shade to estimate the shape of the ski slope. But he cannot yet identify people by their faces alone. He has to use other visual cues, such as their walk, the length of hair or the shape of their eyebrows, to make a guess at who they are.

The scientists said Mr May's experience demonstrated the complex development of sight during early childhood, which involved more than simply sending visual signals from the eyes to the brain.