What is Heliotherapy(Light therapy or phototherapy )?

Heliotherapy is the science conducted on the positive effects of the sun and is an effective tool in boosting the body's immune system.

Further detail on Heliotherapy:

Light therapy or phototherapy consists of exposure to specific wavelengths of light using lasers, LEDs, fluorescent lamps, dichroic lamps or very bright, full-spectrum light, for a prescribed amount of time. It has proven effective in treating Acne vulgaris, seasonal affective disorder, and for some people it has ameliorated delayed sleep phase syndrome. It has recently been shown effective in non-seasonal depression. Proponents claim demonstrable benefits for skin conditions such as psoriasis and, more controversially, a degree of "skin rejuvenation."