Does Light go Beyond Vision?

To make the point that light goes far beyond just our ability to see, our comments are kept to a minimum so as you can make this determination for yourself based on what science has to say in the research excerpts below.

These cover the endocrine system (glands that excrete directly into the bloodstream), blood pressure, and the human organism. We highlighted in Bold the highly pertinent information. The Hollwich study concludes in summary, that under equal conditions, the full-spectrum fluorescent tubes produced significantly less of the "stress hormones" ACTH and cortisol, than were found with the widely used standard cool-white lamps. "In other words, from the standpoint of health, this broad spectrum tube is much better tolerated regarding the endocrine response of the human body than the standard cool-white one." (Page 94 of Hollwich's book, "The Influence of Ocular Light Perception on Metabolism in Man and in Animal") Klin Monatsbl Augenheilkd 1989 Nov;195(5):284-90 [Effect of light on the eye on metabolism and hormones] [Article in German] Hollwich F, Dieckhues B. Numerous metabolic parameters in serum and urine were examined in 110 cataract patients before and after cataract surgery. The marked reduction in light passing through the eye due to opacities (vision less than 1/10) leads to characteristic metabolic and hormonal disturbances. ACTH and cortisol production decreases, metabolism slows down and due to an adrenal insufficiency for which the pituitary is responsible there are characteristic changes in the cortisol-dependent metabolic processes. In addition, an "energetic action" of the light affecting the hypothalamus via the retino-hypothalamic pathways (the "energetic portion" of the visual pathway) was proved in patients who were blinded by cataract and had metabolic disturbances as a result. Postoperatively, after elimination of the lens opacities, the metabolism and hormones of the same patients returned to normal. As a result of restoration of exogenous light stimulation to the diencephalon-hypophysis system via the retinohypothalamic pathway ("energetic pathway" of the optic system) the metabolism and hormones returned to normal during the patients' stay in the hospital. These comparative investigations in the same patients before and after cataract extraction provide for the first time irrefutable scientific evidence of the influence of light via the eye on the human organism. PMID: 2557485 [PubMed - indexed for MEDLINE] Ann Physiol Anthropol 1992 Jan;11(1):45-9 Physiological responses to illuminance and color temperature of lighting. Kobayashi H, Sato M. Department of Physiological Anthropology, Kyushu University of Design Sciences. The present study was designed to examine the effects of illuminance and color temperature of room lighting. Four male students volunteered as subjects. Each of them performed a calculation task for 95 minutes under nine different lighting environments consisting of a combination of three levels of illuminance (320lx, 1000lx and 2000lx) and three levels of color temperature (3000 degrees K, 5000 degrees K and 7500 degrees K). Three types of fluorescent lamps were used as a light source to vary the color temperature. Blood pressure, critical flicker frequency (CFF) and accommodation time of eye movements were measured every 30 minutes during the task. The accommodation time was significantly influenced by the illuminance level and both the relaxation time and contraction time were prolonged under 2000lx. The diastolic blood pressure was significantly affected by the color temperature level and increased under 7500 degrees K. As for the CFF, the interaction between illuminance and color temperature was significant. These results mean that not only the illuminance but also color temperature produces physiological effects. The present study may be the first to recognize the effect of color temperature on the blood pressure. PMID: 1567519 [PubMed - indexed for MEDLINE] For other pertinent topics, see left navigation bar and view topics below:

The Joy of Seeing Colors!
Color for Professionals
Does Light Go Beyond Vision?
Our Bulbs and Glare
Our Bulbs and UV Radiation
Photosensitivity
Children and Light
Seniors and Light
Light and Animals

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