January 31 1997

By Michael Field

Colours are extreme on Pingelap Atoll in Micronesia but due to a mysterious genetic flaw many of its people see it all in shades of grey.

Around 10 percent of the 1,500 Pingelapese are known as "mas kun" or "shut eyes" because they suffer achromatopsia -- true colour blindness.

Worldwide achromatopsia affects only one person in every 33,000.

Ketson Johnson, the Pingelapese publisher of the Micronesia Focus newspaper, says there is no achromatopsia in his immediate family, but ever since he was a child he has known people who suffered.

"In Pingelap the lagoon is blue, very blue, the reef is a shimmering blue and the greenery is very lush," he said in an interview. "There are great extremes in colours and yet these people can see none of this."

Pingelap is a densely crowded low-lying atoll of 715 hectares, 257 kilometres southeast of Pohnpei, the capital island of the Federated States of Micronesia, a nation of hundreds of tiny islands spread over 2,500 kilometres at the Equator between Japan and Australia.

Johnson wrote of his home island in his newspaper recently, discovering cousins with achromatopsia who had suffered most of their lives.

"As they told me their stories I had tears in my eyes, it was so hard for them."

He finds it so strange that he and his spouse do not have it, but their children could -- or their grandchildren.

"It seems that it has no pattern and has been passed on selectively within an afflicted family."

No one knows how the Pingelapese became colour blind.

"Some blame it on a super typhoon that leveled the island in early 1700s and killed all but few Pingelapese who were left with the burden of re-population," Johnson reported.

"Was the breeding too close genetically that cause some mutation in genes that affected the eye of some offsprings?

"Others blame it on the effect of the intense glare of the sandy beaches on Pingelap on which the women trotted to and from for their morning and evening swims in the sea during pregnancy.

"Others attribute it to the ghosts of the pre-Christian era where black magic and demon worship were common in Pingelap.

"Still others blame it as a curse acquired from the whalers who traded with the islanders in the 1700s and 1800s."

The legends have it that the island's leading chief, Isohpahu, killed himself over a derogatory remark made to him. Later his ghost visited a woman and a daughter was conceived. She was the first to be colour blind.

Pingelapese used to call it "soumwahu en eni" or "the illness from the ghosts" but now with recognition of its genetic cause, mas kun, which can also translate as "sight without light", is used.

Johnson says many sufferers complain about the insensitivity they feel from normal sighted people.

A woman told him of suffering in school for many years when she was seated at the rear of the classroom and her teacher used coloured chalks, never knowing she was colour blind.

Another told of how she could not explain to her five-year-old daughter, who does not have the problem, that she could not differentiate colour when shopping for her child's school uniform.

Johnson said some of the people had been taken to the US where they had been studied, but no cure and no cause was ever forthcoming. They discovered, however, that sunglasses made a difference.

"Sunglasses are really good, they can walk and they can read well," Johnson said.

"They see very well at night, better than you and I."

Copyright: Michael Field