The measurements of compounds of electromagnetic radiation of light emitted diodes (LED) sources of light on the basis of the LED type «Acriche» of Seoul Semiconductor Company. Their effect on the functional state of visual, central nerves and cardiovascular systems in 4 healthy male volunteers, engaged in fulfillment of precise visual work in conditions of 6-day laboratory experiment, was investigated. The study of visual work capacity and other physiological functions at illumination on a test surface 180-200 lx showed that changes in their parameters depended on the color temperature of the used LED -4000 and 7900 К. Preliminary recommendations on application of LED sources of light in systems of industrial illumination are given.