Health and Vision

Light affects humans in at least two ways: it enables us to see and it regulates our bodies' rhythms such as the sleep/wake cycle. Different types and levels of light can affect a person's ability to see clearly, identify people and objects, and drive safely. It can also increase sleep efficiency of older adults and reduce symptoms of seasonal affective disorder, or SAD, felt by many people during winter months.

The Light and Health program at the LRC strives to better understand how the retina converts light signals into neural signals to the brain and how lighting can be used to promote health and well-being of those suffering from circadian disorders.

Publications

Light at Night - There is growing interest in the role that light plays on human health, particularly nighttime exposure to short-wavelength (blue) light. Although a logical link may exist between light at night and an increased risk for diseases, it is important to point out that an empirical, scientific link between light at night of a given amount and spectral composition, and an increased risk of disease in humans has not yet been made.

Exposure to Early Evening Sunlight in Spring Delays Sleep Times - In the spring, later sunset and extended daylight exposure delay bedtimes in teenagers, according to researchers at the LRC. Biologically, this increased exposure to early evening light in the spring delays the onset of nocturnal melatonin, a hormone that indicates to the body when it’s nighttime. This extended exposure adds to the difficulties teens have falling asleep at a reasonable hour. Paper published in Chronobiology International.

Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students. - Scientific paper published in Neuro Endocrinology Letters.

Preliminary evidence that both blue and red light can induce alertness at night. - Scientific paper published in BMC Neuroscience.

A personal light-treatment device for possibly improving sleep quality in the elderly: Dynamics of nocturnal melatonin suppression at two exposure levels. - Scientific paper published in Chronobiology International.

A novel lighting system for postural control and stability in seniors - Scientific paper published in Lighting Research and Technology.

Light Therapy for Sleep Disorders and Depression in Older Adults - Scientific paper published in Clinical Geriatrics. (2008)

A proposed 24 hour lighting scheme for older adults - Scientific paper published in Lighting Research and Technology.

A New Approach to Understanding the Impact of Circadian Disruption on Human Health - Scientific paper published on Journal of Circadian Rhythms.

Developing Architectural Lighting Designs to Improve Sleep in Older Adults - Scientific paper published in The Open Sleep Journal.

View more Light & Health publications

Related Programs

Life Sciences in Lighting - New internship program
Light & Health - Visual, circadian systems
Capturing the Daylight Dividend - Using daylighting
Solid-State Lighting - Improving, using LEDs
Daysimeter User Group - Special lighting measuring device

Projects

LRC Study Challenges Claims that Satellite Images of Outdoor Lighting Predict Breast Cancer Incidence - A recent LRC study found that satellite images of outdoor lighting are unrelated to actual light levels reaching the eye. These results challenge previous studies linking satellite images of outdoor lighting with increased incidences of breast cancer. .

Lack of Morning Light is Keeping Teenagers Up at Night - The first field study on the impact of light on teenagers’ sleeping habits finds that insufficient daily morning light exposure contributes to teenagers not getting enough sleep.

View the official press release by clicking here.

Read more about Light and Health studies here.

View a video clip about this story from "Voice of America" here.

Lighting Research Center named recipient of U.S. Green Building Council’s 2008 Green Building Research Fund Grant - The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute has earned the notable distinction of receiving one of only 13 first-ever research grants awarded by the U.S. Green Building Council (USGBC).

Circadian Math: One Plus One Doesn’t Always Equal Two - In a new study published in the June issue of Neuroscience Letters, researchers have demonstrated that when it comes to the circadian system, not all light exposure is created equal.

New Approach Sheds Light on Ways Circadian Disruption Affects Human Health - A study by researchers at the LRC provides a new framework for studying the effects of circadian disruption on breast cancer, obesity, sleep disorders, and other health problems.

New Research May Decode Data from Rodent Cancer Studies for Use in Human Comparisons: Scientists quantify light as a circadian stimulus in breast cancer research - A new paper may help cancer researchers decode results in laboratory studies of light and cancer risk that use mice and rats.

New Math: Two Plus Two Equals Three - Researchers at the LRC are working to better understand and quantify light as a stimulus for the circadian system.

LRC Tool Measures Light Exposure for Circadian System - Overview of the Daysimeter, a tool to measure light reaching the retina and circadian system.

LRC Researchers Use Blue Light to Treat Sleep Disturbances in the Elderly - Study shows blue light exposure in the early evening is effective at consolidating the sleep patterns of the elderly.

Framework Developed for Testing How Lighting Can Affect Human Health - A new model postulates the mechanisms by which humans process light for the circadian system.

LRC Probing Key to Good Night’s Sleep for Persons with Alzheimer’s - A pilot study by LRC researchers has found that Alzheimer's patients sleep better through the night when they are first exposed to blue LED lighting a few hours before going to bed.