The time modern children spend on electronic screens has significantly increased. Data shows that school-aged children aged 6 to 12 spend an average of more than 3 hours a day on devices such as smartphones, tablets or televisions, and some teenagers even spend as much as 7 hours. This high-frequency and prolonged use of digital devices exposes the eyes to a large amount of high-energy visible blue light with wavelengths ranging from 400 to 490 nanometers. Studies show that exposure to such light, especially within one to two hours before going to bed, can inhibit melatonin secretion by up to 50% or more, significantly disrupting the circadian rhythm. For instance, a study published in the journal Scientific Reports followed 100 children aged 8 to 12 and found that the group that used screens before going to bed had an average delay of about 20 minutes in falling asleep and a 15% decrease in sleep quality scores. Against this backdrop, choosing the right blue light glasses for children, especially those lenses that can filter out a specific proportion (such as 30% to 50%) of harmful blue light, has become one of the solutions considered by many families, aiming to improve sleep initiation efficiency and the overall sleep cycle.
From the perspective of alleviating digital visual fatigue, children wearing anti-blue light glasses may also bring benefits. Staring at screens for long periods of time can lead to a significant decrease in the frequency of blinking, from the normal 15 to 20 times per minute to only 5 to 7 times. This increases the evaporation rate of tears by approximately 30%, which is an important factor contributing to the rising incidence of dry eye syndrome and visual fatigue in children. The report of the American Optometry Association indicates that over 30% of school-aged children report regular visual discomfort symptoms such as dry eyes, soreness or blurred vision. blue light glasses help reduce the perceived stress of the visual system when processing high-contrast and high-brightness screen content by reducing the intensity of blue light reaching the retina. A controlled experiment published in the journal Ophthalmology & Physiological Optics in 2022 showed that children wearing effective blue light-filtering lenses had an average reduction of 0.25 days in accommodative lag (the degree of insufficient accommodative response) and a decrease of approximately 22% in subjective visual discomfort scores after completing a continuous 45-minute online learning task. It indicates that it has certain efficacy in alleviating regulatory spasms and visual fatigue.
Although research on the long-term cumulative damage of blue light to the retina is still ongoing, laboratory evidence indicates that high-intensity blue light in specific bands has photochemical toxicity. In vitro experiments have shown that when retinal pigment epithelial cells are exposed to high-intensity blue light with a wavelength of approximately 480 nanometers, their cell mortality rate is significantly higher than that of the control group. Given that children’s lenses are more transparent than those of adults, allowing more short-wavelength light to penetrate, their retinas may face a higher potential risk of light damage. Therefore, from the perspective of preventive protection, wearing qualified blue light glasses during children’s prolonged use of electronic devices (such as more than 2 hours per day) may help reduce the risk of long-term cumulative exposure. Of course, it is crucial to choose products that comply with optical standards (such as EN ISO 12312-1), have clear spectral filtering parameters (for example, indicating blue light blocking rate or specific band transmittance), and have excellent optical quality (low aberration, high transmittance). Inferior lenses may instead increase the visual burden due to distortion or color cast.
It is worth noting that blue light glasses is not a universal solution. The effects vary from individual to individual, and the best protection strategy should be comprehensive. The American Academy of Pediatrics suggests that in addition to considering protective glasses, strict screen time management should be implemented (for example, it is recommended that children aged 2 to 5 do not exceed one hour per day), and the “20-20-20” rule (looking at objects 20 feet away for 20 seconds every 20 minutes) should be promoted. This can effectively reduce the incidence of adjustment fatigue by about 40%. At the same time, ensuring that the ambient light is sufficient (with an illuminance of 300 to 500 lux being appropriate), the screen brightness ADAPTS to the ambient light (avoiding being too bright or too dark), and outdoor activities are arranged regularly (for at least one hour a day), these measures have been proven to have more significant benefits for children’s vision development and myopia prevention and control (reducing the incidence of myopia by about 25%). Therefore, when considering equipping children with anti-blue light glasses, it should be regarded as an optional component of the overall vision health management strategy rather than the sole reliance.