Ordinary colorblindness is almost always partial. People who have it confuse colors, such as green and red, but don't see completely in black and white. Achromatopsia (AYE-CHROME-uh-TOHP-EE-AH) -- total genetic colorblindness -- is surpassingly rare. It occurs in only one person in thirty-thousand. The condition makes people painfully sensitive to light and and unable to see fine details; making it difficult for them to read. On a tiny island in the South Pacific called Pingelap (PING-guh-lap) one in TEN people are totally colorblind. Oliver Sacks, the neurologist and author of "The Man Who Mistook His Wife for a Hat", travelled to Pingelap to see how individuals and the community adapted to this genetic quirk. His new book, "The Island of the Colorblind", is part travel writing, part cultural anthropology. Sacks told Minnesota Public Radio's Stephen Smith that the islanders have invented myths to explain the prevalence of colorblindness. | D-CART ITEM: 1805 | TIME: 4:26 | OUTCUE: "...my island phase"