D65 certified Spectrum
Only high-end Degré K luminaires are D65 certified. This means that they perfectly reproduce natural daylight, unlike almost all of the luminaires on the market which simply simulate it by imitating its sole chromaticity (color temperature).
True natural light at the D65 spectrum has only advantages over a simulation of daylight: fully preserved biological rhythms, maximum visual acuity, perfect color recognition, and unparalleled comfort. On a daily basis, the difference is immediately felt: you tire less quickly and you work much more efficiently at the end of the day.