Ambient light intensity is signaled directly to hypothalamic areas that regulate energy metabolism. Observational studies have shown associations between ambient light intensity and plasma glucose and lipid levels, but human data on the acute metabolic effects of light are scarce. Since light is the main signal indicating the onset of the diurnal phase of physical activity and food intake in hu...

Baehr, Erin K., Louis F. Fogg, and Charmane I. Eastman. Intermittent bright light and exercise to entrain human circadian rhythms to night work. Am. J. Physiol. 277 (Regulatory Integrative Comp. Physiol. 46): R1598–R1604, 1999.—Bright light can phase shift human circadian rhythms, and recent studies have suggested that exercise can also produce phase shifts in humans. However, few studies have ...

PURPOSE Bright light has been shown a powerful inhibitor of myopia development in animal models. We studied which temporal patterns of bright light are the most potent in suppressing deprivation myopia in chickens. METHODS Eight-day-old chickens wore diffusers over one eye to induce deprivation myopia. A reference group (n = 8) was kept under office-like illuminance (500 lux) at a 10:14 light...

I this issue, Özdemir and colleagues1 have shown that treatment of severe major depression can now be greatly improved by safe, simple, and readily available bright light treatment. Patients may benefit within a week. Moreover, the benefit persisted throughout 8 weeks of observation even after the bright light treatment was discontinued. What seemed unique in this new study is the focus on hosp...

Bright light can influence human psychophysiology instantaneously by inducing endocrine (suppression of melatonin, increasing cortisol levels), other physiological changes (enhancement of core body temperature), and psychological changes (reduction of sleepiness, increase of alertness). Its broad range of action is reflected in the wide field of applications, ranging from optimizing a work envi...

We had previously reported on the effect of exposure to light on the human digestive system: daytime bright light exposure has a positive effect, whereas, evening bright light exposure has a negative effect on the efficiency of dietary carbohydrate absorption from the evening meal. These results prompted us to examine whether the light intensity to which subjects are exposed in the evening affe...

Limited research has compared the circadian phase-shifting effects of bright light and exercise and additive effects of these stimuli. The aim of this study was to compare the phase-delaying effects of late night bright light, late night exercise, and late evening bright light followed by early morning exercise. In a within-subjects, counterbalanced design, 6 young adults completed each of thre...