Problems arise when it still feels like "daytime" at night because of artificial light from TVs, smartphones, digital devices, and LED bulbs. The body gets confused, your biological clock is set back, and you fail to produce enough melatonin at the right time to induce sleep. Some people are more sensitive to the effects of light at night and some more resistant, but large amounts of nighttime light cause problems for just about everyone.
A popular fix? Blue light blocking glasses: orange, red, or amber lenses that filter out blue wavelengths, supposedly letting you watch TV, scroll on your phone, or just leave the lights on at night without killing melatonin production.
How Do Blue Light Blocking Glasses Work?
Blue light blocking glasses reduce the activation of intrinsically photosensitive retinal ganglion cells (ipRGCs), which respond to blue light and help establish circadian rhythms. By filtering blue light, these glasses theoretically allow melatonin production to proceed normally, improving sleep quality.
Do Blue Light Blocking Glasses Really Help?
The evidence is mixed, but some studies have reported positive effects. For example:
- In one study involving pregnant women, melatonin levels increased earlier in the night among women wearing the glasses compared to women who didn’t. They also had higher levels of melatonin.1
- Glasses prevented the typical melatonin suppression from blue light exposure among healthy (male) teens and healthy young adults.2,3
- In teens, wearing the glasses at night while using devices improves objective (sleep efficacy and latency) and subjective (self-rated sleep quality) measures of sleep.4
- Overall, blue light blocking glasses do seem to help people fall asleep faster (sleep latency).
The Most Cited Study
Probably the most cited study involved 20 adults randomly assigned to wear either blue-blocking glasses or clear lenses at night. Wrist monitors tracked their sleep, and participants provided subjective reports. The results?
- Subjectively, things got better. They got sleepier earlier and reported fewer awakenings during the night.
- Objectively, though, things were unchanged or even got “worse.” They didn’t sleep as long. In fact, total time asleep was actually (non-significantly) longer in those who wore no glasses.
This raises a key question: what matters more—subjective or objective effects? If it feels like you slept better, fell asleep quicker, and didn’t wake up as much, but the sleep tracker says otherwise, which do you trust?
I say subjective effects matter more. If you feel more rested, you are more rested.
When Don’t Blue Light Blocking Glasses Help?
One of the most common marketing claims for blue light blocking glasses is that they help with “eye strain” or eye fatigue, but most published research has failed to find any real effect.
Likewise, there’s no real evidence that they reduce headaches.
My Personal Take
I used to wear blue light blocking glasses religiously. Then, after selling Primal Kitchen, I had more time to breathe. My wife and I started watching TV or a movie to wind down in the evenings, and I stopped wearing the glasses. Watching TV without the full color spectrum just isn’t as enjoyable.
To my surprise, my sleep didn’t suffer. But I also get full morning sun exposure and spend a lot of time outside during the day, which strengthens my circadian rhythm and makes me more resilient to nighttime blue light.
That said, I still use the glasses when I travel overseas. If I need to shift my circadian rhythm quickly and avoid jet lag, I wear a pair at night to kickstart melatonin production.
Final Verdict
If you’re already getting regular morning sunlight, exercising, and maintaining a solid circadian rhythm, they might not make much difference. But if you struggle with sleep, have trouble falling asleep, or live a mostly indoor lifestyle, they’re probably worth a try.
