When and how should I use artificial light for health?

Use artificial light strategically: bright light can help you feel awake in the morning, while dim, red light is the better option if you must stay up at night. It does not fully replace sunlight for daytime circadian benefits.

• Before sunrise: Turn on bright overhead lights if you need to be awake. A desk light box rated around 10,000 lux is another option; use it briefly—about 5–10 minutes—and stop or reduce exposure if it causes headache or excessive euphoria. Regular household lighting generally cannot reproduce sunlight’s full wake-promoting effect. 1 2
• Prefer outdoor sunlight when available: Artificial light is not a complete substitute. For morning alertness and sleep timing, get outside for sunlight; on heavily overcast days, spend longer outdoors. 3
• For red-light therapy: The discussed red/near-infrared protocols used specific wavelengths—670 and 790 nm—early in the day, within three hours of waking. Keep the source at a comfortable distance; never look at light that is painful or makes you squint. The transcript notes that this research is recent and more data are needed. 4
• If you must work or be awake late: Choose red light and keep it as dim as you can while still doing the task. The rationale discussed is that sufficiently dim red light is less likely than other light to suppress melatonin or raise nighttime cortisol. 5
• At bedtime: Reduce bright artificial light and aim for a dark sleep environment; even dim light exposure at night can interfere with circadian and sleep-related processes. 6