In recent years blue-light-blocking glasses have become a popular tool to help with sleep. They work by blocking blue light wavelengths emitted by smartphones, tablets, and television screens, to prevent stimulation.
The light you see includes a segment of wavelengths part of an electromagnetic spectrum. They are all captured by the eye and translated into white light by your brain. Visible light wavelengths range in power, as well as their effect on your body.
Light does more than help you see. Light exposure helps regulate your natural 24-hour circadian clock that controls sleep and wake cycles, hormonal activity, hunger, digestion, and other bodily processes.
Blue light, in particular, can have an impact on sleep and alertness.
During the day, you want exposure to blue light because it helps synchronize your body clock and keep you awake and alert. You get it naturally from the sun, but when the sun sets, most people start getting it from the screens on their various devices.
It is possible this exposure can disrupt circadian rhythm by tricking your body into thinking it’s daytime, thus making it difficult to fall asleep. It is also possible that exposure inhibits melatonin production, the sleep hormone, and potentially stimulates hormones that keep you awake.
Blue light glasses aim to filter out this light so your body can go through its natural cycle and help you get ready for bed.
There is some data to suggest they may help people with insomnia, but for the most part, it is unclear what kind of an effect they have. Further, it’s hard to know what you’re getting: most commercially available blue-light blocking glasses or coatings added to prescription glasses are not standardized.
With that being the case, it can be hard to tell which light wavelengths are being blocked.
Surer ways of limiting blue light exposure include turning off screens 2-3 hours before bed or activating blue-light removing software on phones, tablets, and computer screens. Getting as much natural light exposure during the day helps, too.
But hey, blue-light-blocking glasses could be worth a shot. It’s possible they could work. If they don’t actually block blue light, the potential for the placebo effect could be high!