There are lots of claims about what blue light can do to our health, and much of it is debated. However, what we do know with more certainty is that blue light is very disruptive for our sleep and circadian cycle, and animal studies suggest blue light may be damaging to eye tissues, including retinal cells and inducing farsightedness by inhibiting growth (more studies needed to confirm this in humans).
Blue light is not all bad. It is part of daylight and is important for making us alert during the day. by suppressing melatonin secretion. So during the day, we don’t want to be blocking out blue light. What we want to do is to avoid blue light at night - which can throw off our sleep cycle and circadian rhythm, making it harder to fall asleep and to get QUALITY sleep. Blue light can impair our deep sleep. It is only during deep sleep that our tissues repair, our brains detox via the lymphatic system, and we secret important hormones like testosterone and growth hormone.
As for damage to the eyes, blue light can cause issues such as dry eye. There is also evidence that blue light can damage photoreceptor cells in mammals. Additionally, there are some studies claiming that blue light is directly related to and can accelerate macular and retinal degeneration in humans, although the strength of these claims is debated among scholars. At the very least, blue light can cause irritation and strain to your eyes through prolonged usage.
You’ve probably heard a lot about blue light-blocking glasses in the media and from health experts promoting them for your protection. There is some evidence that they work for both eye health and sleep cycle. Small studies have shown that wearing blue light-blocking glasses can help reduce symptoms associated with prolonged exposure to blue light from screens, including headaches, blurred vision, dry eyes, and eye strain, fatigue, pain, itchiness, and irritation (although there are also studies showing they have no effect - so we need more studies in order to draw conclusions) - let your symptoms be the guide until we know more.
Stronger evidence supports the use of blue light blockers at night to aid sleep and protect our circadian rhythm, which in turn can impact our hormonal and overall health. Decreasing blue light exposure in the evening has been shown to increase melatonin production and decrease the amount of time it takes to fall asleep.
Limiting exposure to blue light can be achieved by staying off devices (I know, I know it’s hard to do) or wearing glasses that block blue light wavelengths for several hours before bed. One study showed that for people who experience delays in falling asleep, which can be caused by blue-light exposure, wearing blue light-blocking glasses in the evening advanced their melatonin production and the onset of their sleep cycle by over 1.25 hours. Another study showed that people with insomnia who wore blue-light blocking glasses for 90 minutes when combined with CBT-i before they went to sleep experienced a significant reduction in sleep latency and stayed asleep for a significantly longer time than those in a control group.
If you are experiencing any of the symptoms mentioned above and look at screens frequently, blue light-blocking glasses may be worth a try. There are several different types of glasses, so you may be asking, “What type of blue light blockers should I wear and when?” Keep reading to learn how to pick quality blue light blockers for maximum benefits!
Blue-light filtering glasses with clear lenses, also known as computer glasses, are meant to be worn during the day to filter a very narrow band of blue light which may be harmful. However, more is not always better here. Blue light naturally helps keep you awake and alert, which is helpful during the day for our attention span, circadian rhythm, and hormone regulation. Therefore, the best blue light glasses should filter around 30% of blue light between 400nm and 495nm.
To make sure that computer glasses with clear or yellow lenses are filtering the right wavelengths, hold your glasses in front of you and check to make sure they reflect blue light off the lenses and not purple or green light - blue light is what is harmful and emitted from screens. Computer glasses are best to be worn throughout the day and evening anytime you are in front of a screen or under artificial light conditions. For this reason, computer glasses can come with or without a prescription. If you wear prescription glasses, you might be able to get a blue light coating or blue-blocking glasses that go over your prescription glasses.
Nighttime blue light-blocking glasses are a little different - they usually have orange or red lenses, which block much more of the blue-light wavelengths than the clear lenses. They are meant to be worn two to three hours before bedtime to reduce issues related to sleep. While clear blue light glasses only block some blue light to reduce symptoms but still keep you awake, dark amber, orange, or red lenses SHOULD block 100% of blue light so that the blue or green wavelengths are not able to disrupt melatonin production or secretion. Wearing the clear glasses (aka computer glasses) will not have any impact on your sleep, but wearing the complete blue light-blocking glasses for several hours before bed will allow you to fall asleep faster and have a more restful sleep.
Blue light glasses of any kind need to be manufactured in optical laboratories to ensure they are effective and quality (many cheap brands are not) and you can check your night time ones by using these charts here.
My favorite brand that I use is BLUblox - my kids and I wear the computer glasses during the day when I work on my laptop and they do online schooling. At night I wear the Crystal Sleep+ glasses after dinner. Check it out and use my code Platefulhealth15 for 15% off.