Phototherapy

Phototherapy, also known as light therapy or heliotherapy, uses light exposure to treat both physiological and psychological problems that are a result from a lack of sunlight. Physical problems aided by phototherapy include skin disorders: chiefly psoriasis but also acne vulgaris, eczema, and neonatal jaundice.

Phototherapy is also used for the treatment of seasonal affective disorder (SAD, depression caused by lack of adequate sunlight in the wintertime) and circadian rhythm disorders such as delayed sleep phase disorder. The use of light therapy makes use of different types and wavelengths of light, and is prescribed for a certain amount of time per day, and sometimes even a specific time of the day.