Photobiology and photomedicine is "maturing as a solid science . . . with documented benefits and ways of using light," says MIT's Dr. Richard Wurtman. "The feeling now is there are going to be some big leaps and major breakthroughs." A sampling of light research findings:

A daily dose of sunlight winds our biological clocks and keeps them on time. West German and Oregon researchers found that a skewed light schedule, as in jet lag, can be corrected with light therapy to minimize disorientation.

Soviet scientist N.M. Dantzsig concluded that "if human skin is not exposed to solar radiation (direct or scattered) for long periods of time, disturbances will occur in the physiological equilibrium of the human system. Sunlight deficiency is most pronounced in people living in the extreme north, as well as in those working in mines or buildings deprived of natural light and to a degree, of residents of big industrial cities."

A recent Harvard study found that a group of healthy elderly veterans showed a 25 percent decrease in their capacity to absorb calcium during a winter month. A similar test group spending eight hours a day under high levels of simulated natural light showed a 15 percent increase in calcium absorption. The ultraviolet rays that group was exposed to was the equivalent of a 15-minute walk outdoors during the summer.

A Swiss study demonstrated that intense doses of simulated natural light given for an hour in the morning and in the evening for one week to "normal subjects" significantly improved general mood and well-being, enhanced alertness and decreased daytime feelings of drowsiness.

A recent one-year study demonstrated the effects of simulated natural light on the productivity and health of keypunch operators working in a windowless environment. Result: 55 percent less overtime, 36 percent less sick leave, and more than a 13.7 percent increase in productivity.