light therapy [AS, leoht + Gk, therapeia, treatment] , the use of natural light or light of specified wavelengths to treat disease. This may include ultraviolet light, colored light, or low-intensity laser light. The eye is generally the initial entry point for the light because of its direct connection to the brain through the retinal hypothalamic pathway, which affects the autonomic nervous system and endocrine function. Light therapy has been used primarily for attention deficit disorders, cataracts, conjunctivitis, headaches, head trauma, hyperactivity, lazy eye, macular degeneration, migraine, night blindness, poor eyesight, stroke, and vision disorders. It has also been effective in treating eczema, fever, psoriasis, addictions, allergies, anxiety, autism, bronchitis, childbirth, glaucoma, insomnia, muscle spasm, premenstrual syndrome, stress, and strep throat. Light therapy complements many other treatments for these and other conditions.
