Ergonomic Lighting Indicator (ELI) is an assessment of lighting quality described in the European standardEN 12464. Lighting quality is an important factor in visual performance and thus lighting
in offices, production halls, stadiums, congress centres, operating theatres, streets, car parks, shop windows and in many other areas plays a decisive role that is directly related to people's activities. The quality of light determines colour rendering as well as over-radiation and shadow effects, too low or too high contrasts and too strong or low colour saturations
. High lighting quality is ensured when the brightness distribution ofthe
lighting is uniform and balanced and the light sources do not have different colour temperatures, when daylight and artificial light have the same colour temperature and thus complement each other and the artificial light does not flicker.