Blue-light glasses are said to reduce eye strain when using computers, improve your sleep and protect your eye health. You can buy them yourself or your optometrist can prescribe them. But do they work? Or could they do you harm? We reviewed the evidence. Here’s what we found.
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What are they?
- Blue-light glasses, blue light-filtering lenses or blue-blocking lenses are different terms used to describe lenses that reduce the amount of short-wavelength visible (blue) light reaching the eyes.
- Most of these lenses prescribed by an optometrist decrease blue light transmission by 10-25%.
- Standard (clear) lenses do not filter blue light.
Blue light is all around us
- Outdoors, sunlight is the main source of blue light.
- Indoors, light sources – such as light-emitting diodes (LEDs) and the screens of digital devices – emit varying degrees of blue light.
- The amount of blue light emitted from artificial light sources is much lower than from the Sun.
Do they reduce eye strain?
Do they help you sleep?
- Six studies evaluated whether wearing blue-light filtering lenses before bedtime could improve sleep quality, and the findings were mixed.
- So we do not yet know whether these lenses affect sleep quality in the general population.
Do they boost your eye health?
We did not find any clinical evidence to support using blue-light filtering lenses to protect the macula (the region of the retina that controls high-detailed, central vision). None of the studies evaluated this.
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Could they do harm? How about causing headaches?
What about other benefits or harms?
- First, most of the studies were for a relatively short period of time, which limited our ability to consider longer-term effects on vision, sleep quality and eye health.
- Finally, we could not draw conclusions about the possible effects of blue light-filtering lenses on many vision and eye health measures, including colour vision, as the studies did not evaluate these.
In a nutshell
- It is unclear whether these lenses affect vision quality or sleep, and no conclusions can be drawn about any potential effects on the health of the retina.
- They can perform a thorough examination of your eye health and vision, and discuss any relevant treatment options.