NEW YORK – The pitch for blue light-filtering glasses is compelling: an easy way to counteract that bleary-eyed feeling that sets in after hours of scrolling on your mobile phone or staring at a laptop.
The evidence for them, though, has largely been lacking. And a new review of 17 studies adds to a growing consensus that they probably do not prevent or relieve eye strain.
The phrase blue light refers to a range of wavelengths of light around people – the sun emits it, and so do screens.
Some experts have wondered whether blue light could be behind “computer vision syndrome” – a condition that encompasses the eye irritation and other issues, including headaches and blurred vision, that many people experience after extended screen time.
But blaming blue light for this is contentious, said Associate Professor Laura Downie of optometry and vision sciences at the University of Melbourne and an author on the new review.
She and the team found that there appeared to be no benefit to using blue light-filtering glasses, compared with just standard lenses, to reduce eye strain. The trials included in the review were relatively small – the largest had 156 participants.
Researchers have long been sceptical that blue-light glasses can curb eye strain, said Professor Mark Rosenfield at the State University of New York College of Optometry.
Previous studies have also typically been small, but several have found that the lenses did not prevent people’s eyes from tiring or getting irritated, and did not appear to improve vision.
The new review found mixed results for blue light-filtering glasses and sleep. Some studies showed improved sleep scores among wearers, while others showed the opposite.
There is evidence that blue light may also take a toll on sleep by inhibiting the brain’s ability to secrete melatonin, the hormone that gets people ready to rest, said Dr Raj Maturi, a spokesman for the American Academy of Ophthalmology.
The amount of blue light that a phone or computer emits is actually quite low, Prof Downie said, which might be why blocking it does not do...