Research excerpts discussing the debilitating effects of cool-white fluorescent lights, how light affects our mind and bodies, and latent flicker from computer monitors.

Many thanks to The University of Iowa Department of Ophthalmology for providing Hollwich, Dieckhues, Hartmann excerpts and articles. Many thanks to these Doctors for their wisdom and insite to investigate and prove that we need to respect and manage our light.

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Dr. Fritz Hollwich (professor, author, researcher Professor of Ophthalmology, University of Muenster, West Germany), said his findings explain the agitated mental and physical behavior of children who spend up to six hours each day in school under artificial illumination (3500 and 3200 1x). He goes on to stress the importance of using light that is closest to natural light.

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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 Metabolsim in Man and in Animal")

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[The effect of natuaral and artificial light via the eye on the hormonal and metabolic balance of man (author's transl)]. [German] Klinishe Monatsblatter fur Augenheilkunde. 171(1) :98-104, 1977 Jul.

Abstract
Examinations of hormone levels in blind persons compared with almost blind and people with normal vision and hormone evaluation with increased artificial light exposure show a definite stimulating effect of light on the human hormonal balance. The effect of light is mediated by an intact perception of light by the eye over an "energetic part" of the visual pathway (Hollwich 1948) - hypothalamus - hypophysis - peripheral endocrine gland. Increasing the intensity of artificial light with "neon-tubes" (fluorescent tubes) leads to "light stress" proved by increased hormone production - especially the stress hormone Cortisol. The belief that artificial light is the same as natural light and that it can fully replace it, is inappropriate in the medical view and needs correction

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Authors
Hollwich F. Dieckhues B.

Title
[Effect of light on the eye on metabolism and hormones]. [German] Original Title Der Einfluss des Lichtes uber das Auge auf den Stoffwechsel und die Hormone.

Source
Klinische Monatsblatter fur Augenheilkunde. 195(5):284-90, 1989 Nov.

Local Messages
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MeSH Subject Headings
*Cataract/pp [Physiopathology]. *Cataract Extraction. Circadian Rhythm/ph [Physiology]. *Corticotropin/bl [Blood]. *Energy Metabolism/ph [Physiology]. English Abstract. Eosinophils/ph [Physiology]. Human. *Hydrocortisone/bl [Blood]. Hypothalamus/pp [Physiopathology]. Leukocyte Count. *Light. Retina/pp [Physiopathology]. Visual Pathways/pp [Physiopathology].

Abstract
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.

Registry Numbers
50-23-7 (Hydrocortisone). 9002-60-2 (Corticotropin).

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Authors
Hollwich F. Hartmann C.

Title
[Influence of light through the eyes on metabolism and hormones]. [French] Original Title L'influence de la lumiere a travers l'oeil sur les metabolismes et sur les hormones.

Source
Ophtalmologie. 4(4):385-9, 1990 Jul-Aug.

Local Messages
Journal not held at the University of Iowa Libraries

MeSH Subject Headings
Animal. Cataract/pp [Physiopathology]. Cataract Extraction. English Abstract. Eye/ph [Physiology]. *Eye/re [Radiation Effects]. Hormones/se [Secretion]. Human. Hypothalamo-Hypophyseal System/ph [Physiology]. *Light. *Metabolism/re [Radiation Effects]. Research. Retina/ph [Physiology]. Retina/re [Radiation Effects].

Abstract
The eye plays a double role: on the one side it is the optic camera, on the other side independent of the optic path ways it is the light receptor which stimulates the retino-hypothalamique pathway of the endocrine-visceral system. To determine this influence, we compared the metabolisme (water balance, blood sugar and blood cell count) as well as the hormones (ACTH, Cortisol) of fifty patients with bilateral almost total cataract, before (practically blind) and after cataract surgery (regain of light). There was a significant difference between the metabolic and hormonal values before and after cataract extraction, reaching physiologically normal levels due to the stimulating influence of light after the operation.

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The American Institute of Architects now recommends that full-spectrum replace lights replace cool-whites in our learning environments where concentration levels need to be at their highest.

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(Click here for research on the use of Glare filters)

The latent flicker of the computer screen causes people to tire more easily, experience difficulty concentrating, make more mistakes, and become more irritable. This is confirmed by recent ergonomic studies conducted by the Christian Bartenbach Group in Innsbruck, Austria.