In the 1980s, NASA’s Jet Propulsion Laboratory (JPL) faced a challenge…
Scientists James Stephens and Charles Miller were grappling with the harmful effects of light in space as well as the dangers of radiation for astronauts’ eyes during welding work.
A protective welding curtain that could absorb and filter the harmful radiation—inspired by none other than birds of prey. These birds, equipped with perfect vision, have eyes that produce tiny oil droplets. These droplets naturally filter out harmful radiation, allowing only beneficial light through.
Harnessing this mechanism, the JPL duo used specialised dyes and zinc oxide particles to replicate the birds’ defense. Their welding curtain was a triumph.
Spotting its broader potential, they transitioned their discovery from welding stations to everyday wear. And thus, the foundational concept for blue-light glasses emerged.
Debunking the Marketing Hype
Understanding blue light’s role is crucial. During the day, blue light is advantageous, promoting alertness and attention and boosting serotonin levels. However, at night, it suppresses our body’s melatonin production, the hormone that encourages sleep.
Many blue light blocking sunglasses companies argue that these lenses improve sleep, reduced eye strain, and even prevent potential retinal damage. But is there truth to these claims?
Contrary to the marketing promises, the consensus among scientists remains skeptical.
First of all, the blue light emitted by our devices is fractional compared to natural sources. Even on an overcast day, outdoor blue light exposure significantly surpasses that from screens. For perspective, consider the difficulty of viewing your phone or laptop screen under bright sunlight.
Another prevailing myth is that blue-light glasses protect our retina from potential damage from the light emitted by computers, handheld devices, LED lightbulbs and even TVs.
In the UK, this claim led Boots Opticians—one of their biggest optical chain retailers—into legal hot water, resulting in a £40,000 (around $56,000) fine due to its “misleading and unsubstantiated” nature.
Recent Scientific Scrutiny
An August 2023 Cochrane review, internationally recognised as the highest standard in evidence-based health care, reached a similar conclusion.
It observed 17 clinical trials from six countries, incorporating data from 619 individuals. Their findings? Blue-light glasses do not provide the immediate benefits they claim to, especially in the realms of visual fatigue and sleep quality.
So, How Can We Improve Sleep?
Instead of reaching for expensive blue-light glasses, consider the following time-tested methods:
- Distance from Screens: It’s advisable to put away devices an hour or two before sleep.
- Screen Time Effects: Be aware that the content and the very act of scrolling can disrupt sleep, regardless of blue light.
- Exercise Regularly: A consistent routine promotes better sleep.
- Mind Your Dinner Timing: Avoid heavy meals close to bedtime. Ideally leave three hours between dinner and bedtime.
- Establish a Bedtime Routine: A regular routine can signal your body to wind down.
- Digital Detox: Reducing exposure to news and social media in the evening can lead to restful sleep.