The average American spends more than seven hours per day in front of a screen, so it is essential to protect our eyes, frequently with blue-light glasses. However, recent research indicates that wearing eyeglasses with a blue-light filter may not preserve your retina, reduce nighttime eye strain from computer use, or improve your ability to sleep.
The report, published in The Cochrane Database of Systematic Reviews, analyzed data from 17 randomized controlled clinical trials conducted over days to months in six countries.
Lead author Laura Downey said she found that using blue-light-blocking glasses may not reduce visual fatigue associated with computer use. She said the brevity of clinical trials could have helped reviewers' ability to consider long-term results.
"It is also currently unclear whether these lenses affect vision quality or sleep-related outcomes, and no conclusions could be drawn about any potential effects on retinal health in the longer term," continued Downie. "People should be aware of these findings when deciding whether to purchase these spectacles."
What is blue light?
The human eye can discern blue light as a part of the visible light spectrum. It is thought to make up around a third of all visible light. Fluorescent lights, LED TVs, computer monitors, smartphones, and tablet screens are examples of artificial sources of blue light.
As blue light is difficult for our eyes to filter, almost all of it enters the front of the eye and travels to the retina, where it is transformed into pictures by cells in the retina. It can eventually damage retinal cells over time and cause problems with vision, including age-related macular degeneration.
According to a National Eye Institute vision study, children are more at risk than adults because their eyes absorb more blue light from digital devices. Blue light glasses are known to be prescribed to reduce eye strain associated with digital devices.
The team added that the study was conducted to answer the ongoing debate about whether using blue-light-blocking lenses is beneficial in ophthalmology.
"Our certainty in the reported findings should be interpreted in the context of the quality of the available evidence."- First author, Sumeer Singh
In addition, blue-light glasses only filter between 10% and 25% of blue light from artificial devices such as computer screens. That blue light is only "a thousandth of what we get from natural daylight," continued Singh.
Singh further said that filtering out high levels of blue light would require the lens to be quite amber, which would significantly impact color perception. He added that there are many marketing claims about potential benefits, such as improving sleep quality and protecting the retina from light damage.
The researchers concluded that the results do not support blue-light-blocking lens prescriptions for the general population and are relevant to a wide range of stakeholders, including ophthalmologists, patients, researchers, and the wider community.
- The Cochrane Database of Systematic Reviews. Blue‐light filtering spectacle lenses for visual performance, sleep, and macular health in adults.
- Cross River Therapy. Average Screen Time Statistics & Facts (Usage).
- All About Vision. How to help children avoid computer vision syndrome.