Background
: Smartphones, computers, tablets, televisions and other digital screens emit blue light, which can have severe consequences on the eyes, including dry or watery eyes, strain and other kinds of irritation. Blue light can also wreck one’s sleep schedule because it disrupts the circadian rhythm.
Blue-light blocking glasses are said to have specially crafted lenses that can filter or block out the blue light emitted from digital screens in order to reduce headaches, eyestrain and sleep issues. The lenses can also purportedly help reduce potential damage to the retina from prolonged exposure to blue light.
The COVID-19 pandemic has done wonders for the blue-light blocking glasses industry, due to a steady rise in screen time. As people spend more time online — working, studying or even ordering food — the demand for blue-light blocking glasses has shot up massively, without any conclusive evidence that these glasses actually reduce eye strain or protect eyes from the effects of blue light. Optical company Zenni sold more than 7 million frames, including 2 million blue light-blocking Blokz lenses in 2020 alone.
According to market research company 360ResearchReports, the global market for blue-light blocking glasses is expected to grow at a compound annual growth rate of roughly 7.6% over the next five years, to reach $28 million in 2024 from $19 million in 2020.
But do blue-light blocking glasses really work and protect eyes from digital screens?
What the science says
According to the American Academy of Ophthalmology, “Blue light-blocking glasses do not improve symptoms of digital eye strain.” The amount of light that comes from a digital screen has not shown to cause any eye disease. In fact, a study by the National Library of Medicine found no measurable UVA or UVB radiation — the most harmful part of light — from computer screens.
The academy explains that while blue light does affect the human body’s circadian rhythm, its natural wake and sleep cycle, the optimal way to avoid sleep disruption is to avoid using digital screens a few hours before bed. Additionally, using night mode on electronic devices in the evening can help.
Another study published by the Ophthalmic and Physiological Optics journal says, “We find a lack of high quality evidence to support using BB spectacle lenses for the general population to improve visual performance or sleep quality, alleviate eye fatigue or conserve macular health.”
The College of Optometrists also “does not support the use of blue-blocking spectacle lenses in the general population to improve visual performance, alleviate the symptoms of eye fatigue or visual discomfort, improve sleep quality or conserve macula health.”
That said, a study done in 2017 suggests that “blue-light filtering spectacle lenses can partially filter high-energy short-wavelength light without substantially degrading visual performance and sleep quality. These lenses may serve as a supplementary option for protecting the retina from potential blue-light hazard.”
An article published in Applied Psychology shows that “wearing blue-light filtering glasses creates a form of physiologic darkness, thus improving both sleep quantity and quality.”
Interestingly, blue-light therapy has demonstrated a positive effect on sleep, mood and motor symptoms in patients suffering from Parkinson’s disease, according to a study by Hindawi.
In conclusion
The jury is still out on this one. Because blue-light blocking glasses are such a new product, there is not enough research to show whether they really protect eyes from digital screens. Scientists are still trying to understand what blue light can do to eyes over time. Until then, the best thing to do in case of any eye discomfort is to consult an ophthalmologist and take any marketing for blue-light blocking glasses with a grain of salt.
