A review of the studies on nonvisual lighting effects in the field of physiological anthropology

Abstract

Here, we review the history and the trends in the research on the nonvisual effect of light in the field of physiological anthropology. Research on the nonvisual effect of light in the field of physiological anthropology was pioneered by Sato and colleagues in the early 1990s. These authors found that the color temperature of light affected physiological functions in humans. The groundbreaking event with regard to the study of nonvisual effects of light was the discovery of the intrinsically photosensitive retinal ganglion cells in the mammalian retina in the early 2000s. The interest of the physiological anthropology scientific community in the nonvisual effects of light has been increasing since then. A total of 61 papers on nonvisual effects of light were published in the Journal of Physiological Anthropology (including its predecessor journals) until October 2018, 14 papers (1.4/year) in the decade from 1992 to 2001, 45 papers (2.8/year) in the 16 years between 2002 and 2017, and two papers in 2018 (January–October). The number of papers on this topic has been increasing in recent years. We categorized all papers according to light conditions, such as color temperature of light, light intensity, and monochromatic light. Among the 61 papers, 11 papers were related to color temperature, 20 papers were related to light intensity, 18 papers were related to monochromatic light, and 12 papers were classified as others. We provide an overview of these papers and mention future research prospects.

A Purkinje image-based system for an assessment of the density and transmittance spectra of the human crystalline lens in vivo

“…In those previous studies, however, the detailed relationships between lens transmittance spectra and visual/non-visual functions could not be investigated because there was no method for assessments of transmittance spectra in vivo. By using the present approach, assessments of lens transmittance spectra and estimation of the spectral quality and quantity of light reaching the retina can be performed objectively, easily, rapidly and accurately, and our approach should make some contributions to various research fields which need to information on retinal illuminance such as studies on non-visual lighting effects 47 , 48 . For non-visual research, for example, relative non-visual photoreception reduction with aging can be estimated from our results for lens transmittance (Fig.…”

Photobiomodulation of the Visual System and Human Health

“…Several recent reviews are available that discuss the impact that electromagnetic radiation has on the eye [46,58], skin [59,60], and other biological functions [61]. In brief, as noted, UV damage is photochemical, not photothermal.…”

Difference in autonomic nervous effect of blue light depending on the angle of incidence on the eye

“…These non-image forming functions were known to be mediated by intrinsically photosensitive retinal ganglion cells (ipRGCs) [2,3], which express melanopsin as the photopigment. Since melanopsin has a specific sensitivity to blue wavelength light around 480 nm [4], blue light stimulation to the ipRGCs is recognized as a central mediator of the nonimage-forming response to light [5][6][7].…”