Evidence on the effects of digital blue light on the eye: A scoping review

Background: Digital blue light is the blue light emitted from light emitting diode (LED) displays, which may be regarded as a health hazard to our eyes and vision. Aim: This review sought to map out evidence on the effects of blue light on the eye from digital devices. Methods: The study design is a scoping review. Peer-reviewed studies published in the last 25 years were sourced from Google Scholar, PubMed, Cochrane and Medline databases. Data were extracted using the relevant search terms followed by thematic analysis. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) framework was utilised to report this process. The Mixed Method Appraisal Tool (MMAT) assessed the quality of included studies. Results: Thirty-seven articles met the eligibility criteria. After the full-text screening, the exclusion of 32 articles resulted in five articles to map. The majority of studies included the indirect measuring of the effects of digital blue light using blue-blocking spectacles on blink rate, critical flicker frequency, near point of convergence and eyestrain. The central theme identified across mapped studies regarding the effects of digital blue light was its role in resultant visual discomfort. Of the five accepted studies, three studies had an MMAT score of 100%, whilst two studies scored 80%, suggesting that their results were reliable. Conclusion: The review concluded that blocking short-wavelength blue light reduced visual discomfort or digital eyestrain. The gap identified was a lack of research on the exposure of digital blue light on the retina in human eyes in vivo and required more investigations to corroborate the animal studies.