BLUE DREAMS
Will tinted glasses that filter out electronic “blue” light really help you to sleep better? We try them on for size
Your bedtime Instagram habit harbours a dark side. According to the University of Houston, exposure to artificial light in the evening can suppress your levels of the hormone melatonin by as much as 58%, reducing the duration and quality of your sleep.
To mitigate this effect, bio-hackers – the kind of people who put butter in their coffee and get IV drips of vitamins – are now ostentatiously sporting tinted specs that filter out blue light. Though the premise might seem logical, scientists aren’t entirely sold on the idea. Visible light exists on the electromagnetic spectrum between 380 nanometres (nm) on the blue end and approximately 700nm on the red. Blue-light glasses filter out rays below 500nm, blocking those to which your body clock is particularly sensitive. However, other light on the spectrum can still upset your circadian rhythm and sabotage your sleep.
“These glasses may be beneficial in the evening, in a room without screens,” explains Stuart Peirson, professor of circadian neuroscience at the University of Oxford. “But you won’t sleep any better after wearing them in front of a bright TV or laptop for an hour. Those devices project a large amount of light across the spectrum. It’d be like putting on sunglasses and staring directly at the sun.”
To make matters shadier, most of these specs don’t specifically state which beams they block. Many (particularly the clear-lens varieties) fail to filter out all rays below 500nm.
“If you can’t see a visible difference with them on, they’re not likely to have any effect,” says Peirson.
If you’re yearning for better rest, here’s a simpler alternative: bask in as much natural light as you can. According to research published in Sleep Health, people who get more sun exposure in the day can be rewarded with up to 46 minutes more shut-eye at night. So, our knockout tip to help you catch more Zs? Simply book in a daily lunchtime walk.