Human Light Response via Skin, Eye and Brain

Ultraviolet light from sunlight unfolds a variety of different photophysical and photochemical activities in human skin, which are controlled and reacted upon by two photoendocrinologically active antagonistic organs in the brain, namely the pituitary and pineal gland, under the control of the eye. There are also two organs for light reception, namely skin and eye. These systems have been attuned by the course of evolution under the frequent influence of sunlight. Human genes only know how to react upon bright light with the spectral composition of sunlight. Understanding this heliotropic logic behind the coordination processes between skin, visual and energetic portion of the retina and photoendocrine regulation in the brain is essential for creating a reliable concept of healthy artificial lighting.