Light has a direct effect on the workings of the body and on our moods. When the sun comes out our spirits rise and we feel more energetic, while insufficient light can lead to depression and lethargy. Light is known to stimulate the pineal and pituitary glands, which correspond to the highest two chakras in yogic medicine. There is much scientific evidence to show that certain chemicals such as melatonin are produced or suppressed by sunlight. Melatonin controls our sleep patterns but an excess can lead to depression and tiredness. Seasonal Affective Disorder , a depression that occurs through the winter, can easily be improved by subjecting an individual to bursts of full-spectrum light. This mimics natural sunlight, exposure to which increases the amount of serotonin produced by the body.

Light therapy is used to treat a range of other problems associated with hormone imbalance. Menopausal and premenstrual problems, infertility and loss of libido have all responded well to light therapy which works directly on the eyes stimulating the pineal gland in the brain. The body needs sunlight in order to manufacture vitamin D, essential for maintaining the health of the bones and skin. Skin disorders such as acne, eczema and psoriasis, as well as the debilitating bone disease osteoporosis, may all benefit from light therapy. In these cases the light is shone on to the skin as well as the eyes. Light therapy is also used to boost the immune system and improve blood circulation.

Each session of therapy involves lying on a couch under an overhanging light, and lasts for about 45 minutes. For acute cases a weekly session is usually recommended at first. People usually respond very quickly to the therapy and after a few sessions find that they only need ‘top-up’ sessions occasionally.

Light therapy is also part of crystal therapy .