Blue-light glasses: useful or marketing? The carousel in 7 images
“Anti-blue-light” lenses promise to protect the retina, reduce eye strain and improve sleep. What the studies really say, in 7 images published on Instagram.
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The carousel, image by image
The text of each carousel page, to read at your leisure or to find a specific piece of information.
Blue-light glasses: useful or just marketing?
Cover image of the carousel: glasses with clear lenses resting on a desk, in front of a computer screen.
Blue light, a normal light
An ordinary component of visible light, located at the end of the spectrum, just after ultraviolet. Unlike UV, blue light passes through the lens and reaches the retina.
Source no. 1, by far: the sun. A day outdoors provides far more than several hours of screen time.
Screens, LEDs: a tiny share. Compared with the sun, the emission from a screen is incomparable.
Does it damage the retina?
To date, no study has shown that the blue light from screens damages the retina at everyday exposure levels.
Where the fear comes from: experiments on cells or animals, at intensities far higher than those of a phone.
What the professional societies say: the American Academy of Ophthalmology does not recommend blue-light-blocking lenses to “protect” the eyes from screens.
“Less eye strain”: the most common promise
Cochrane systematic review, 2023: blue-light-filtering lenses show no demonstrated benefit for screen-related eye strain. A Cochrane review pools and evaluates all the available trials: it is the highest level of evidence.
The real explanation: this strain comes from dry eye — in front of a screen, we blink far less — and from the effort of focusing. Not from blue light.
And for sleep?
This is the only area where blue light really plays a role: in the evening, it can delay melatonin and push back sleep onset.
But be careful: the specific effect of filtering lenses remains modest and inconsistent in studies.
At least as effective: cutting back on screens before bedtime, or switching on night mode. And these two reflexes cost nothing.
In front of screens, what really helps
The 20-20-20 rule: every 20 minutes, look at something 20 feet away (about 6 metres) for 20 seconds.
Blink deliberately: blinking spreads the tear film, it is the first step against screen-related dryness.
Above all: a suitable correction. An inaccurate prescription tires the eyes far more than blue light. If your eyes burn, it is often dry eye that needs treating.
Should you buy a pair?
There is no risk in wearing them: if you have a pair and feel more comfortable, keep them.
Little proven benefit: they are neither essential, nor a substitute for an eye examination.
Key points: at the levels emitted by screens, blue light does not damage the retina. Eye strain that sets in deserves an examination, not a filter.
Sources: Cochrane review, Singh et al. 2023 · American Academy of Ophthalmology. For information only; does not replace a consultation.
Going further
This carousel summarises the essentials in a few images. The subject is covered in more depth on the dedicated page of the website: Blue-light glasses: useful or marketing? (full article).
