Changing light colors reduces molecular, hormone, and behavior disruptions caused by nighttime light exposure

Filtering short wavelengths <480 nm from light exposure prevented nocturnal suppression of melatonin secretion and increased cortisol levels.

• Non-image-forming responses to light can influence molecular, neuroendocrine, and neurobehavioral variables.
• Short wavelengths peaking around 450-480 nm are particularly effective in inducing acute and circadian phase-shifting effects.
• Filtering out short wavelengths <480 nm reduced the impairment of subjective alertness, mood, and performance on vigilance tasks at 0800.
• No significant increase in sleepiness or fatigue was observed with the filtered light compared to unfiltered exposure.
• Further filtering of wavelengths <460 nm or partial filtering <480 nm did not yield significant improvements over unfiltered light.

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