Background and Purpose:
The rapid increase in the use of digital devices such as smartphones, tablets, and computers has significantly changed the visual environment of modern life, leading to prolonged near work and increased exposure to artificial ...
Background and Purpose:
The rapid increase in the use of digital devices such as smartphones, tablets, and computers has significantly changed the visual environment of modern life, leading to prolonged near work and increased exposure to artificial light sources. These changes have resulted in a growing number of individuals experiencing ocular fatigue and visual discomfort, commonly referred to as Digital Eye Strain (DES). Previous studies have reported that over 60% of digital device users experience visual fatigue symptoms, including blurred vision, dryness, and accommodative instability. Among the various factors contributing to DES, exposure to harmful light wavelengths such as ultraviolet (UV), blue light (BL), and near-infrared radiation (IR) has been shown to negatively affect ocular physiology. Blue light in particular induces oxidative stress in retinal pigment epithelial cells and disrupts circadian rhythm by suppressing melatonin secretion. UV exposure contributes to lens opacity and cataract formation, while IR exposure can increase ocular surface temperature and cause thermal fatigue.
This study aims to evaluate the physiological effects of functional spectacle lenses that selectively block UV, BL, and IR wavelengths on accommodative response and microfluctuations, providing objective evidence for their role in alleviating digital eye strain.
Methods:
Thirty participants in their twenties with mild myopia were recruited for this study. A randomized crossover design was implemented using three lens conditions: UV-blocking lenses, BL-blocking lenses, and IR-blocking lenses. Each participant underwent accommodative response testing and accommodative microfluctuation (HFC, High-Frequency Component) analysis under identical visual stimuli conditions for each lens type.
Additionally, subjective visual fatigue was assessed using the Computer Vision Syndrome Questionnaire (CVS-Q). The study investigated both objective and subjective parameters to determine whether different spectral filtering characteristics influence accommodative stability and perceived fatigue. The experimental setup was designed to simulate typical near-work conditions, with all measurements performed in a controlled indoor illumination environment.
Results:
The accommodative response demonstrated statistically significant differences among lens conditions (p < 0.05). Both the BL-blocking and IR-blocking lenses showed more stable accommodative responses compared with UV-blocking lenses, indicating a reduction in accommodative lag and improved response consistency. The HFC values, representing microfluctuation amplitude, did not differ significantly among lens types (p > 0.05), suggesting that short-term exposure may not produce measurable changes in high-frequency components.
Subjective fatigue scores from the CVS-Q did not differ significantly across lens conditions; however, participants reported slightly greater comfort with BL- and IR-blocking lenses. Correlation analysis between HFC and CVS-Q scores showed no significant association, implying that physiological stability and subjective fatigue may be influenced by separate mechanisms.
Overall, both BL and IR blocking demonstrated positive effects on accommodative function and visual comfort, while UV blocking primarily provided long-term ocular protection.
Conclusions:
This study demonstrates that optical filters designed to block harmful wavelengths—particularly blue light and near-infrared radiation—can improve accommodative stability and contribute to the reduction of digital eye strain. These effects may be attributed to decreased neural and thermal stress on the ocular system.
Although the experiment was limited to short-term exposure and young myopic subjects, the results suggest that multi-wavelength protection lenses combining UV, BL, and IR blocking may offer comprehensive benefits by simultaneously reducing photochemical, thermal, and oxidative stress on the eye.
Further research should include diverse age groups and longer exposure durations to evaluate adaptive changes in accommodative stability and fatigue over time.
Ultimately, this study provides foundational evidence that functional spectacle lenses can enhance visual comfort and protect ocular health in digital environments.