Whether Johann Wolfgang v. Goethe actually demanded “Mer light!” on his deathbed remains unclear. What is clear, however, is that natural light is indispensable for our daily lives. It determines our biorhythm and ensures, among other things, that vitamin D is formed via irradiation on the skin. What’s more, sunlight and artificial light are also used in medicine to treat diseases.
Sun and more
Medical treatments using light include phototherapy and heliotherapy. Phototherapy uses artificial light sources such as UV or white light lamps, while heliotherapy uses natural sunlight. In medicine, the following phototherapeutic applications are distinguished:
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Infrared light: heat radiation for rheumatic diseases or chronic inflammations (e.g. inflammation of the sinuses).
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White light: irradiations in sleep disorders and winter depression (SAD).
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UV radiation: skin diseases such as neurodermatitis, psoriasis or acne, jaundice in newborns.
The different forms of light act quite differently on the body. Infrared light acts mainly through heat. It increases blood circulation, relaxes muscles and relieves pain – therefore, infrared lamps are used for muscle tension, rheumatic symptoms or even diseases of the sinuses.
UV light acts directly on the skin. Irradiation can calm the immune system in the upper layers of the skin. This is especially important in allergic diseases such as neurodermatitis, as they are based on an overactive immune system. Inflammatory skin diseases can also be alleviated. In psoriasis, the radiation has a growth-inhibiting effect and can thus stop the increased formation and desquamation of skin cells.
In pediatrics, UV light is used to treat jaundice in newborns. During the changeover to the child’s own blood production after weaning from the mother, the maternal blood cells break down. Initially, the hemoglobin breakdown products can only be excreted in small quantities by the kidneys and would harm the child if they remained in the body. Upon UV irradiation, the dye then breaks down into highly soluble components that can be completely excreted in the urine.
