Wald, professor of Biology, has completed a series of experiments which show that every color-blind person lacks one of three pigments basic to normal human color vision.

In an interview which appeared in the latest issue of The New Yorker, Wald discussed this discovery and other results of his recent research.

There are three pigments involved in normal human vision, Wald said, which researchers have known about since the early nineteenth century. Nearly three years ago Wald explained, he development a simple procedure for actually measuring these pigments in the human eye.

Using his new method, Wald and his associates were able to examine the pigments without removing them from the human retina. Eventually, the experimenters were able to measure the pigments in single light-sensitive cones of the retina, Wald said.

Wald found, he said, that each of the three essential pigments is made in the same way. They are produced by joining Vitamin A aldehyde to one of three different proteins, he said.

Last year Wald applied his procedure to researching color-blindness, using volunteers drawn primarily from his Nat Sci 5 course. His experiments revealed, he said. "The answer to color blindness is absurdly simple,"--each of the color-blind volunteers possessed only two of the three essential pigments, he said.

Wald's theory also established that there are three kinds of disease, depending on which of the pigments is missing in the eye.

His research has not yet established why the pigment is missing or how to supply it but he is continuing his research, The New Yorker article suggested.