Human beings tend to think that light-sensitive molecules exist only in the eyes, but they come in four major types: rhodopsin (in the retina, which absorbs light for vision), hemoglobin (in red blood cells), myoglobin (in muscle), and most important of all, cytochrome (in all the cells). Cytochrome is the marvel that explains how lasers can heal so many different conditions, because it converts light energy from the sun into energy for the cells. Most of the photons are absorbed by the energy powerhouses within the cells, the mitochondria.
