Light therapy has been around since ancient Egypt.  Egyptian healers built temples of light where patients spent days, weeks or months convalescing under the rays of the sun. Temple attendants brought food, removed waste, and ensured that the patient remained exposed to constant solar radiation. 

The Greeks and Roman also used light as a healing modality. 

Meanwhile, in 3rd century BC China, the science of acupuncture was developed, based on the idea that living organisms are electromagnetic beings with energy channels, or nadi, running in distinct paths throughout the body. All disease, or "dis-ease," is caused by a disruption in this electrical energy grid.  [more coming soon]