Blue light glasses are unlikely to help eye strain – here’s what does

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 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 don’t prevent or relieve eye strain.

The phrase blue light refers to a range of wavelengths of light that are all around us – the sun emits it and so do screens. In recent decades, some experts have wondered whether blue light could be a culprit 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 Laura Downie, an associate professor 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 to 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 Mark Rosenfield, a professor 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’s evidence that blue light may also take a toll on sleep by inhibiting our brain’s ability to secrete melatonin, the hormone that gets us ready to rest, said Dr Raj Maturi, a spokesman for the American Academy of Ophthalmology and a retina specialist at the Midwest Eye Institute.

The amount of blue light that a phone or computer emits is actually quite low, Dr Downie said, which might be why blocking it doesn’t do much to ameliorate eye strain. But if you spend four or more hours a day on a computer, you’re nonetheless at risk for screen-induced eye irritation, she added. The way we use our eyes when we stare at a screen for long periods of time, especially close up to our faces, can cause discomfort.

Dr Downie and other experts recommended a few tips that may help.

LUBRICATE YOUR EYES

Part of the reason your eyes might ache is that you blink far less when glued to a screen, said Dr Craig See, an ophthalmologist at Cleveland Clinic’s Cole Eye Institute. This means that your eyes dry out more easily. If you regularly experience eye strain, consider using eye drops three to four times a day, Dr Maturi recommended.

“I often tell people that if you know that your eyes tend to start to feel gritty, sandy, almost as if there’s something in them after using the computer, you might even try putting artificial tears in before sitting down,” said Dr Joshua Ehrlich, an assistant professor of ophthalmology and visual sciences at the University of Michigan.

GIVE YOURSELF A BREAK

Eye health experts often recommend the “20-20-20” rule: Every 20 minutes, take a 20-second break to look at something 20 feet (6 metres) away. This exercise helps the eye muscles relax, Dr Maturi said. However, some researchers have suggested that 20-second breaks may not be long enough.

REDUCE GLARE

It’s important to consider the light in your entire room, not just the kind coming from your computer. Reflections and glares on your screen can strain your eyes, Dr Downie said. Make sure your computer is positioned to minimise reflections from light sources and reflective surfaces like windows and glass doors.

PLACEMENT IS EVERYTHING

Keep the centre of your screen just below eye level, and if you’re experiencing eye strain, try moving your computer farther away from you – the ideal range is generally around 20 to 30 inches (approximately 50cm to 76cm) away from your head, Dr Downie said.

The same advice goes for your phone: Your eyes have to work harder when you hold your phone close up to your face, said Dr Rosenfield. Try to hold it at least 16 inches (40 cm) away, he suggested.

GET HELP

If you’re consistently feeling eye strain, and none of these solutions are working after three or four weeks, seek out an eye specialist, Dr Maturi advised.

WHAT ABOUT SLEEP?

There are a few tools that might be equally effective at helping you sleep as special glasses, Dr Rosenfield said. For example, some smartphones automatically shift screens to warmer tones after a certain hour. The American Academy of Ophthalmology recommends people use apps like F.lux to change the colour of their screens at night, which can help emit less blue light.

By Dani Blum © The New York Times Company

The article originally appeared in The New York Times.