Effect of visible light on biological objects: Physiological and pathophysiological aspects

Visible light is a necessary condition for the existence of life on the Earth. The food and oxygen consumed by humans, directly or mediately, are products of photosynthesis: conversion of light energy into the energy of chemical bonding in organic matter. Visible light not only provides photosynthesis in plants; it is also involved in the regulation of many reactions (from molecular to behavioral) in the animal world. This review is devoted to the questions concerning the role of light in the life of biological objects and the physical mechanisms of interaction of visible light with matter. The effect of light on the molecular and physiological reactions of a human and its microflora is analyzed. The existing methods and the application potential of light effects in diagnostics and therapy are considered.