For years, the New England Journal of Medicine was skeptical, but now it says scientific evidence shows light therapy does help people with severe seasonal depression. Science Specialist Ed Yeates reports.

For most of us, clouds come and go with little or no effect. But for someone who has what's called Seasonal Affective Disorder, prolonged cloudy days bring on depression.

For years, researchers have been trying to find out if manmade light shining in the eyes of a S.A.D. person could make them feel better again. Within the past five years, patients with S.A.D. here in Utah and elsewhere claimed the lights made a dramatic change.

"IT MAKES MY ATTITUDE AND MY EMOTIONS FEEL A LOT LIGHTER AND I JUST FEEL BETTER ABOUT LIFE IN GENERAL WHEN I'VE USED IT."

Despite all these testimonials, scientists remained skeptical until studies published in the Archives of General Psychiatry two months ago pulled off double-blind or placebo experiments which kept the science honest.

ED YEATES, SCIENCE SPECIALIST: "AGAIN, THE THERAPY IS SIMPLE - THE DOSAGE ONLY ONCE A DAY. IN THE MORNING, SAY BEFORE GOING TO SCHOOL OR WORK, THE PATIENT SIMPLY LOOKS INTO THE LIGHT AT ABOUT THIS DISTANCE FOR THIRTY MINUTES."

HENRY SAVAGE, APOLLO LIGHTS: "THESE PEOPLE WHO GET OUT OF SYNC FOR SOME REASON - MAYBE GENETIC - FIND THAT EARLY MORNING LIGHT IN TWO OR THREE DAYS WILL MAKE THEM FEEL LIKE SUMMERTIME."

The light is not as bright as sunlight but bright enough - researchers believe - to trigger sensors in the brain.

Circadian rhythms or the body's 24-hour clock - need to be adjusted everyday in some people. Researchers say perhaps the light in the morning re-synchronizes the brain - adjusting two chemicals called melatonin and seratonin.

This Utah-based company is now making 50 therapeutic lights a day, distributing many to the National Institute of Mental Health, the Mayo Clinic, and Harvard and Cornell Universities - to name a few.