I Didn’t Know That . . .

Q: Do people who were born blind dream, and do they “see” things when they do?

A: People who were born blind or who lose their vision before the age of 5 certainly do have vivid and detailed dreams, but they do not see images in them, experts say. People who lose their vision after the age of 7 can continue to have detailed visual dreams for 20 to 30 years. For those who lose sight between the ages of 5 and 7, however, the situation is less clear: Some seem to see images in dreams and others do not. The conclusions are based both on reports from blind people and monitoring of rapid eye movements, which are generally believed to occur during the events. Those who are congenitally blind or who lose vision before 5 do not have the rapid eye movments or have only very small ones.