Light therapy is the use of natural or artificial light to treat various ailments, but primarily depressive and sleep disorders. It may be administered by a physician, physical therapist, psychiatrist, or psychologist–or done on one’s own with proper instruction from a trained professional. While exposure to the full-spectrum wavelength of natural sunlight is considered the best form of light therapy, it is not always possible for many people to get outdoors. Therefore, light therapists often recommend treatment with simulated sunlight from light boxes.