Seeing the Light
The residents of Schuyler Ridge Residential Health Care, a senior care facility in upstate New York, have had an easier time getting to the bathroom recently—not because of additional staffing or new medication, but thanks to "landing lights" that guide their nighttime journey. When their feet hit the ground, motion-activated LEDs illuminate the edges of the bed and doors, making their rooms look like tricked-out import cars.
According to Dr. Mariana Figueiro, program director at Rensselaer Polytechnic Institute's Lighting Research Center, which developed the setup, it reduces falls by enhancing the cues that feed residents' "perceptual vision"—visual information that helps us orient ourselves. Illuminating horizontal and vertical surfaces (like door frames) increases the sense of spatial orientation, improving balance.
The project is one example of the Lighting Research Center's efforts to improve patient safety. Emphasizing the connections between hard science and real-world applications, the LRC has studied the benefits of light for night-shift nurses, Alzheimer's patients, and premature babies. Night-shift nurses, for example, are less prone to error when exposed to high amounts of white light, or low amounts of blue light, because it stimulates the body's circadian system and increases alertness.
Photo courtesy of Credit Lighting Research Center
For the same reason, Alzheimer's patients exposed to blue light at certain times of the day have been found to sleep better at night, improving their overall quality of life. And in a study published in the Journal of Pediatrics, premature babies exposed to cycled light and dark in the ICU were found to gain weight faster than babies exposed to constant near-darkness.
Yet it isn't just a matter of installing lights. The LRC has also explored the basic science of light's effects on humans. They've found that it's not all "visual"—dependent simply on the amount of light, regardless of its source (the "photon is a photon is a photon" school of thought, jokes Dr. Figueiro). Rather, the LRC has expanded its research to attempt to quantify the effects of different qualities and implementations of light, such as the "landing lights" at the nursing home, which affect the "perceptual" system, or the pulses of light that alter the "circadian" system.
"Light isn't just for vision," says Dr. Figueiro. "It can affect health and well-being through different pathways, and the characteristics for each system are different. The biggest challenge for design is 'How do you come up with solutions that meet the needs of all of them?'"
And—as with the practice of medicine more generally—find ways of quantifying the effects of light on medical outcomes. "Evidence-based design requires objective measures," Dr. Figueiro says.