For years, blue light-filtering glasses have been offered as a way to protect the eyes from the blue light emitted by computer and device screens. While blue light is also present in natural sunlight, manufacturers of such lenses claim that due to the increasing time spent in front of digital LED devices, our exposure to this light has risen, potentially affecting eye health and sleep patterns.
New International Research
Focus on 17 Studies from Six Countries An international research team led by Laurie Downie and Sumeer Singh from the University of Melbourne has now examined some of these claims
The team investigated the effects of eyeglasses with blue light filters compared to glasses without such filters on eye strain, retinal protection, and improvements in sleep quality. They analyzed data from 17 controlled studies conducted in six countries. These studies involved between 5 and 156 participants and ran for up to five weeks.
No Advantages
Regarding eye fatigue from computer use, the analysis found no short-term advantages of blue light filters. “Currently, it is also unclear whether these glasses affect visual quality or sleep-related outcomes,” Downie said in a statement. Therefore, the team could not draw conclusions about potential long-term effects on retinal health, something individuals should consider before purchasing such glasses, according to Downie.
Blue Nonsense
Sparse Data and Questionable Basis These results do not surprise Michael Bach from the University Medical Center Freiburg. The vision researcher has long been skeptical of the supposed benefits of blue light filters and refers to them as “blue nonsense” in his blog. The authors of the Cochrane study point to a rather sparse data situation and emphasize that due to the short follow-up time of the studies, no statements about longer-term results can be made. They argue that larger and longer studies would be necessary.
Bach does not see this need: “The amount of blue light coming from the screen is ridiculously small compared to what you get on a sunny day outside. And the eye is built for that.” Furthermore, blue light is not much more effective than other colors of light. Long-term studies would not change this biological fact.
Look Into the Distance
Screen Work Does Have Consequences However, Bach does acknowledge that there can be strain on the eyes from activities like prolonged computer use. Staring in the same direction or distance for extended periods can lead to reduced blinking, which can result in dry eyes.
Therefore, individuals who work on screens for extended periods should look into the distance for at least five minutes every hour or take a break and move around every half hour. Regarding the impact of blue light on sleep, Bach explains that it’s mainly about avoiding brightness before bedtime. However, the difference between blue light and other colors of light is relatively small. “All of these tips may sound trivial, but they are correct,” says the expert, who is a member of the German Ophthalmological Society (DOG).
Blue Light Filters Side Effects
Blue Light Filters May Affect Mood The Cochrane authors also discuss the side effects of blue light filters, noting that discomfort, headaches, and worsened mood have been reported when wearing such glasses, likely related to the act of wearing glasses in general. These side effects are also observed with glasses without blue light filters.
Bach adds that such lenses can alter color perception, which could be significant for graphic designers, for instance. Furthermore, mood alteration is at least conceivable since the filters allow less light to pass through. “This could potentially be important for people prone to depression.”