In healthy adults who have had limited sleep, exposure to a simulated sunrise light before waking may improve how good they feel, compared to exposure to dim light or blue light.

After two nights of limited sleep, people exposed to light that mimics a natural sunrise have higher cortisol levels when they wake up compared to those exposed to blue light or dim light.

In healthy adults who slept only six hours for two nights, exposure to blue light in the morning helped maintain cognitive function, while light that mimicked dawn improved it further, compared to dim light, which caused a decline in performance.

In healthy adults who have had limited sleep for two nights, exposure to blue light in the morning may shift the timing of melatonin release to occur earlier than when exposed to dawn-like or dim light.

Being around too much blue light at night, like from phones or lamps, can mess with your sleep and your body's internal clock, making it harder to fall asleep and feel rested.