The only reasonably BIO-COMPATIBLE light at night is the light from THERMAL SOURCES with a lot of INFRARED. Fire, Candles, Incandescent, Halogen. Light made by HEAT, Not Electronics. Light that follows BLACKBODY RADIATION. Blackbody physics is the foundation of how Natural light works. The Sun is basically a giant blackbody radiator. It emits a continuous, smooth spectrum of light. Incandescent bulbs mimic this. Their filament’s heat causes it to emit light through blackbody radiation which produces a broad & continuous spectrum. Life evolved under blackbody spectra. LEDs on the other hand are just a hack. They use fancy tricks to fake what incandescents do naturally. View quoted note →