
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, January 5, 1995                   TAG: 9501050056
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A9   EDITION: METRO 
SOURCE: ASSOCIATED PRESS
DATELINE: BOSTON                                 LENGTH: Medium

SOME BLIND PEOPLE SENSE LIGHT

RESEARCH SUGGESTS some blind people's brains perceive sunlight, even though their eyes don't - which keeps their internal clocks in working order.

Here's a mystery solved: How do some totally blind people fall asleep at the same time each night, even though they cannot tell light from dark?

For many blind people, in fact, insomnia is a major problem. About half the time, they have something like jet lag. Their bodies' clocks are way out of sync with the clock on the wall. They toss and turn at night and nod off during the day.

The reason for their sleeping problems seems clear: The brain needs exposure to sunlight to keep its internal clock running on a precise 24-hour schedule. Otherwise, it falls behind about a half hour each day.

For a fortunate minority of blind people, however, sleep at the appropriate time comes easily.

Now scientists think they know why: Their brains can see light, even when their eyes cannot.

The discovery may yield important clues to how the brain keeps time in everyone, blind or not. It also raises questions about the common practice of removing blind people's eyes for cosmetic reasons.

The research, conducted by Dr. Charles A. Czeisler and others from Brigham and Women's Hospital in Boston, was published in today's issue of the New England Journal of Medicine.

The mother of one of the people Czeisler studied had refused to let doctors take out her son's eyes, because she hoped a medical breakthrough someday would restore his sight.

``Little did she realize that she was preventing her son from being subjected to an intractable lifelong sleep disorder,'' he said.

by CNB