Blue Light & Your Circadian Rhythm
Humans have evolved to rise with the sun and go to sleep after sunset. Also known as our circadian rhythm, this 24-hour cycle takes us from sleepiness to alertness at regular intervals. A well-functioning circadian rhythm helps us rise, get through our day effectively and fall asleep at night.
Blue light is key to a well-functioning circadian rhythm. Roughly twelve hours after our eyes are exposed to blue light, melatonin is released in the brain, leading to drowsiness and sleep. The good news is that the sun is well equipped to give us blue light between 7:00 a.m. and 11:00 a.m. (when light is 450-500nm wavelength). And when the sun isn’t available (think Alaska in the winter and very rainy places), folks have figured out how to get blue light from man-made lamps.
Problems arise when we are exposed to blue light when we shouldn’t be. Blue light comes from lots of man-made sources — namely, our screens. Television, computers, phones and digital clocks all emit blue light and this light is hitting us at all hours — not just that ideal morning segment — throwing off the ideal 12-hour sleep/wake cycle. So, avoid looking at screens late into the evening. While many phones have a “night mode” or “night shift” that reduces blue light emissions, it’s still not advisable to bring your phone or tablet to bed.
Blue Light & Your Skin
Blue light therapy helps break down bilirubin into products that are easily eliminated, reducing jaundice in newborns.
Blue light is antibacterial and can decontaminate hospital and clinic rooms. It can kill bacteria that causes hospital-acquired infections. It can also kill skin bacteria and be used to improve the symptoms of psoriasis, reduce eczema lesions and treat atopic dermatitis (under the care of a dermatologist)
Blue Light Benefits
Exposure to blue light can positively affect us in many ways from better sleep to fewer skin blemishes.
- Helps regulate circadian rhythm
- Boosts alertness
- Helps memory and cognitive function
- Elevates mood
- Helps with jaundice in newborns
- Helps relieve acne and other skin conditions
- Can kill bacteria
Blue Light Cautions
Avoid blue light at night to maintain a healthy circadian rhythm. And too much exposure can also affect eyes negatively.
Blue light harmful effects:
- Disrupts circadian rhythm
- Contributes to digital eyestrain
- May increase the risk of macular degeneration
The takeaway here, get outdoors in the morning and let the sun work its magic. Consider taking a morning walk (it’s one of the positive morning rituals our readers identified) outside and you’ll not only set yourself up for a great night’s sleep, but a positive day, too.