You searched for: “ionotherapy
ionotherapy, ultraviolet therapy
1. The process of electric current traveling through a salt solution, causing migration of the metal (positive) ion to the negative pole and the radical (negative) ion to the positive pole; or the introduction of various ions into tissues through the skin by means of electricity.
2. The use of ultraviolet radiation in treatment of diseases, particularly those affecting the skin.
3. Ultraviolet therapy, it the use of ultraviolet electromagnetic radiation in the treatment of disease, usually of the skin, is used in humans, but not commonly employed in veterinary medicine.

This is the part of the sun's spectrum that causes sunburn and tanning.