Do We Really Need Blue Light Filtering Glasses to Protect Our Eyes?
Written by Theint Aung
Edited by Jasmine Jeon and Carolyn Chiu
Dec 11, 2022
Edited by Jasmine Jeon and Carolyn Chiu
Dec 11, 2022
Research
In the age of COVID-19, public health and social measures to limit the transmission of the virus have resulted in a drastic increase in screen time. A recent study reported that on average adolescents spend 7.70 hours per day on their screens, an increase from 3.8 hours per day before the pandemic (Nagata et al., 2022). This increase is dangerous since research shows that prolonged screen use can result in a condition known as computer vision syndrome (CVS) which involves several eye-related problems such as blurred vision, dry eye, redness, and headache (Singh et al., 2021). Today, CVS affects 60 million people worldwide with 1 million new cases each year, and this number is further expected to increase due to the pandemic.
It has long been thought that blue light emitted from screens may be harmful to the eyes, and could possibly even be responsible for CVS. Therefore, lenses that reduce blue light transmission to the eye have been marketed to reduce eye strain. Blue-blocking lenses can be bought on Amazon for as low as $10 or some can be as expensive as $95. So, do blue light filtering glasses actually work?
In 2021, a group of researchers from Australia investigated if blue-light-blocking lenses were effective in reducing the signs and symptoms of eye strain caused by screen usage, specifically associated with monitor screen use (Singh et al., 2021). They recruited 120 participants aged 18-40 years who habitually used computers with a diagnosis of CVS. To minimize participant bias, the tested participants did not have prior knowledge of eye care or spectacle lens products.
The participants were randomly separated into 2 groups based on either positive or negative advocacy groups. In the positive advocacy group, the participants had to watch a video that presented the lenses from a positive perspective, and in the negative advocacy group, the lenses were presented in a negative way. The participants were further randomized into receiving blue blocking or placebo lens. Blue blocking lens filters blue light by blocking transmission below 400 nm and placebo lenses were UV-coated lenses that did not filter blue light.
First, the participants had to go through a series of pre-task measurements that included both subjective and objective measures of eye strains. Next, participants were given the randomly assigned lens. Then, they were asked to carry out 2 hours of computer tasks involving spreadsheet data entry and data checking. Throughout the task, their blinking was monitored. After data collection, post-task measurements, which were similar to the ones taken before the tasks were taken. Finally, the researchers measured the mean change from pre-task to post-task measurement results. After analysis, the researchers found that there was no significant difference between blue-blocking and control spectacle lenses and no effect of advocacy type. Therefore, blue-blocking spectacle lenses were shown to be ineffective against computer-induced eye strain, regardless of the manner in which they were advocated.