[Effect of light on the eye on metabolism and hormones]

Numerous metabolic parameters in serum and urine were examined in 110 cataract patients before and after cataract surgery. The marked reduction in light passing through the eye due to opacities (vision less than 1/10) leads to characteristic metabolic and hormonal disturbances. ACTH and cortisol production decreases, metabolism slows down and due to an adrenal insufficiency for which the pituitary is responsible there are characteristic changes in the cortisol-dependent metabolic processes. In addition, an "energetic action" of the light affecting the hypothalamus via the retino-hypothalamic pathways (the "energetic portion" of the visual pathway) was proved in patients who were blinded by cataract and had metabolic disturbances as a result. Postoperatively, after elimination of the lens opacities, the metabolism and hormones of the same patients returned to normal. As a result of restoration of exogenous light stimulation to the diencephalon-hypophysis system via the retinohypothalamic pathway ("energetic pathway" of the optic system) the metabolism and hormones returned to normal during the patients' stay in the hospital. These comparative investigations in the same patients before and after cataract extraction provide for the first time irrefutable scientific evidence of the influence of light via the eye on the human organism.