Interventions for the management of computer vision syndrome: a systematic review and meta-analysis

Computer vision syndrome: a comprehensive literature review

Computer Vision Syndrome is a growing health concern in the digital age, with a reported prevalence of 69.0%. It is caused by screen-related, environmental, ergonomic, and physiological factors, affecting diverse demographics. The COVID-19 pandemic significantly amplified CVS due to increased screen time for remote work, online learning, and social media use, with studies reporting symptoms in up to 74% of individuals. Unique visual challenges from digital screens, including reduced clarity and glare, exacerbate symptoms like dry eyes and discomfort, especially in those with uncorrected vision. Understanding CVS is crucial for mitigating its impact through effective prevention and management strategies. This study explores the causes, diagnosis, management, and prevention strategies of CVS by synthesizing recent findings from optometry, occupational health, digital health, and ergonomics. It also highlights emerging trends such as AI, wearables, and augmented reality while providing practical management strategies. A narrative review of literature from 2014 to 2024 was conducted, focusing on PubMed-indexed, peer-reviewed articles, including meta-analyses and systematic reviews, with priority given to recent, highly cited studies.

Investigating computer vision syndrome and associated factors before and during the COVID-19 pandemic: A comparative cross-sectional study in faculty members

BackgroundOne of the most significant impacts of the COVID-19 pandemic on human societies was the transformation of face-to-face training (F2F) into distance education (DE) processes.ObjectiveThis study aimed to investigate computer vision syndrome (CVS) before and during the COVID-19 pandemic and identify the risk factors that may lead to increased incidence of CVS in university professors due to DE.MethodsUsing an online questionnaire, occupational and demographic information, hours of computer, laptop, smartphone, and tablet usage before and during the COVID-19 pandemic were collected. In the second part, participants were asked to report the frequency of occurrence and severity of 16 CVS symptoms over the past year and the last 7 days. The third section of the questionnaire recorded CVS risk factors such as ergonomic status of workstations, during virtual live training (VLT) and offline content creation during the COVID-19 period.ResultsThe prevalence of CVS was 9.03% before COVID-19 and 34.19% during COVID-19. The cumulative incidence of CVS was 25.48%. The mean ± SD of the CVS final score significantly increased before (6.82 ± 4.29) and during COVID-19 (8.48 ± 7.11) (p < 0.001). Associated factors with CVS revealed using Univariate analyses (OR >1; 95% CI 0.75-11.27, p < 0.05).ConclusionDE has led to increased prevalence and incidence of CVS in university professors during the COVID-19 pandemic. It appears that associated factors with CVS such as increased usage time of smartphones can contribute to increase CVS in university professors.

Interventions to prevent visual fatigue during robotic surgery

The robotic surgeon is at risk of visual fatigue from prolonged viewing of the video display resulting in digital eye strain and use of the three-dimensional binoculars resulting in accommodative stress. Symptoms of digital eye strain include blurred vision, dry eyes, eyestrain, neck and back ache, diplopia, light sensitivity, and headaches. Vergence or accommodation-related symptoms include blurred near or distance vision, difficulty refocusing, and diplopia. Beneficial ergonomic interventions to manage digital eye strain during robotic surgery include appropriate lighting, improved neck positioning, optimal screen positioning, improved image parameters, screen breaks, optimising environmental factors, and eye exercises. Correction of refractive error, use of lubricating eye drops, and blink efficiency training to induce motor memory have been shown to be effective in reducing visual fatigue. Vergence-accommodation mismatch can be reduced with slower movement of the camera, screen breaks, and correction of refractive error. Robotic surgeons should adopt these simple and non-invasive interventions to minimise visual fatigue.

Meta-analysis of visual fatigue based on visual display terminals

BACKGROUND

This study aims to explore the impact of using visual display terminal (VDT) on the visual fatigue of operators through meta-analysis.

METHODS

The terms "VDT", "visual fatigue", "eyestrain", and "viewing distance" were selected from the Wangfang, China National Knowledge Infrastructure (CNKI), Web of Science, Springer, and Science Direct online databases. The retrieval time was from the establishment of the database to the present. All clinical studies related to the analysis of the effects of VDT use on visual fatigue were available. The included studies were screened, and after quality assessment, basic data and outcome index data were extracted. The count data were represented by relative risk (RR) and 95% confidence interval (CI). The measurement data were represented by the mean value (MD), standard deviation (SD), and 95% CI. Review Manager 5.3 (RevMan5.3) was employed to analyze the included indicators. Funnel plots were drawn using RevMan5.3 to analyze potential publication bias. The incidence of visual fatigue, lens use time, blink interval, and other indicators were compared between the VDT group and the control (Ctrl) group. Meanwhile, the incidence of eye fatigue and blurred vision in the two groups was counted.

RESULT

The incidence of eye pain, fatigue, blurred vision, teary eyes, and dry eyes in the VDT group significantly exceeded that in the Ctrl group. Meanwhile, the dry eye score, as well as the scores for eye fatigue, discomfort, and blurred vision, were significantly higher in the VDT group compared to the Ctrl group.

CONCLUSIONS

The results indicate that the use of VDT has a significant impact on visual fatigue.

Prevalence of Computer Vision Syndrome and Its Risk Factors in a Spanish University Population

OBJECTIVES

To determine the prevalence of digital eye strain or computer vision syndrome (CVS) and its risk factors in a university population (University of Valladolid, Spain).

METHODS

An anonymous cross-sectional online survey was conducted in a university population [staff (lecturers and administrative employees) and students (undergraduate, master's, and PhD)], including two validated questionnaires (Ocular Surface Disease Index [OSDI] and the 17-item Computer-Vision Symptom Scale questionnaire [CVSS17]) and questions about sociodemographic data and visual display terminal use. The prevalence and risk factors for CVS (CVSS17≥29) (multivariate logistic regression model) were calculated.

RESULTS

One thousand nine participants responded to the survey (35.2±15.2 years; 64.1% women). The mean OSDI and CVSS17 questionnaire scores were 18.9±15.6 and 31.5±6.4, respectively, and 35.4% of the respondents had dry eye symptoms (OSDI>22). The total prevalence of CVS was 65.4% (95% CI 62.1-68.3). Undergraduate students showed the highest CVS prevalence (72.6%; P <0.01), which was significant. In addition, women, participants younger than 36 years old, contact lens wearers, and subjects with dry eye symptoms reported a statistically higher CVSS17 score ( P ≤0.01). In the multivariate model, significant factors associated with the presence of CVS ( P ≤0.03) were female sex (OR=2.10; 95% CI 1.54-2.88), dry eye symptoms (OSDI>22) (OR=16.98; 95% CI 10.36-27.84), VTD use ≥6 hr daily (OR=1.96; 95% CI 1.09-3.52), and being an undergraduate student (OR=2.23; 95% CI 1.54-3.24).

CONCLUSION

A high prevalence (65.4%) of CVS was found among the Spanish university population, with the undergraduate student group having the highest prevalence (72.6%). Female sex, more than 6 hr/day of visual display terminal use, being an undergraduate student, and dry eye symptoms significantly increased the risk of CVS in the university population.

Evaluating the efficacy and safety of therapeutic interventions for corneal neuropathy: A systematic review

Corneal neuropathy involves corneal nerve damage that disrupts ocular surface integrity, negatively impacting quality-of-life from pain and impaired vision. Any ocular or systemic condition that damages the trigeminal nerve can lead to corneal neuropathy. However, the condition currently does not have standardized diagnostic criteria or treatment protocols. The primary aim of this systematic review was to evaluate the efficacy and safety of interventions for treating corneal neuropathy. Randomized controlled trials (RCTs) that investigated corneal neuropathy treatments were eligible if the intervention(s) was compared to a placebo or active comparator. Comprehensive searches were conducted in Ovid MEDLINE, Ovid Embase and clinical trial registries from inception to July 2022. The Cochrane Risk-of-Bias 2 tool was used to assess study methodological quality. Certainty of the body of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Overall, 20 RCTs were included. Evaluated interventions comprised regenerative therapies (n = 6 studies), dietary supplements (n = 4), anti-glycemic agents (n = 3), combination therapy (n = 3), supportive therapies (n = 2) and systemic pain pharmacotherapies (n = 2). Nine RCTs were judged at high risk of bias for most outcomes. Definitions for corneal neuropathy in the populations varied substantially across studies, consistent with lack of consensus on diagnostic criteria. A diverse range of outcomes were quantified, likely reflecting absence of an agreed core outcome set. There was insufficient evidence to draw definitive conclusions on the efficacy or safety of any intervention. There was low or very low certainty evidence for several neuroregenerative agents and dietary supplements for improving corneal nerve fiber length in corneal neuropathy due to dry eye disease and diabetes. Low or very low certainty evidence was found for neuroregenerative therapies and dietary supplements not altering corneal immune cell density. This review identifies a need to standardize the clinical definition of corneal neuropathy and define a minimum set of core outcome measures. Together, this will provide a foundation for improved phenotyping of clinical populations in studies, and improve the capacity to synthesize data to inform evidence-based care. Protocol registration: PROSPERO ID: CRD42022348475.

Exploring the Effect of Trataka (A Yogic Cleansing Technique) and Cold Eye Pack on Eye Strain During COVID-19 Pandemic: A Randomized Three-Arm Trial

Objective: Computer vision syndrome is a major global public health concern affecting >60 million individuals globally. Yoga and naturopathy practices can reduce visual fatigue and strain. The present study attempted to explore the effect of trataka that is, a yogic cleansing technique and cold eye pack on visual strain and fatigue. Subjects: Three hundred volunteers from an IT company were recruited following inclusion and exclusion criteria. Intervention: The subjects were randomly distributed in three groups, that is, trataka, cold eye pack, and waitlist control group with an allocation ratio of 1:1:1. Outcome measure: Visual Fatigue Scale and Visual symptoms checklist (VSC) was administered at baseline and end of 2 weeks. Repeated measures analysis of variance (RM-ANOVA) with Bonferroni corrections was used to test the difference across the groups. Results: All the variables were similar at the baseline among the groups. Significant changes in the within-group analysis occurred in both the trataka and cold eye pack groups. The RM-ANOVA revealed significant differences in the VAS and VSC (p = 0.001) and the post hoc analysis suggested that there were significant differences in both the trataka and cold eye pack group when compared with the control group (p = 0.001); however, there was no differences between the trataka and cold eye pack group in both the scales (p = 1). Conclusions: The results of the present study suggest that a trataka and cold eye pack for 14 days improves self-rated visual strain and fatigue among IT professionals with computer vision syndrome. Clinical Trial registration number: CTRI/2020/11/029003.

Patient barriers and facilitators for making environmental and behavioral modifications for dry eye in the United States

BACKGROUND

Managing dry eye disease (DED) is expensive. Often, prescribed treatments improve clinical signs but not patient-reported symptoms. In large surveys, clinicians and patients ranked environmental and behavioral modifications among the most important DED-related research priorities. Our purpose was to investigate the barriers to and facilitators of use of these modifications by patients with DED in the United States and how their use may be impacted by socioeconomic status (SES).

METHODS

Using Qualtrics, we conducted an anonymous online survey of adults with DED living in the United States in August to September 2022. Patients were identified through the Dry Eye Foundation, Sjögren's Foundation, and a DED clinic in Colorado. We used an established index for classifying respondent SES based on education, household income, and employment. Outcomes included use of environmental and behavioral modifications and barriers to and facilitators of their use.

RESULTS

We included 754 respondents (SES: 382 low, 275 high, and 97 unclear). Most were aged 18 to 49 years (67%), female (68%), and White (76%) and reported dealing with DED for ≤5 years (67%). The most frequent modifications were taking breaks to rest eyes (68%), increasing water intake (68%), and using hot/cold compresses (52%). For these three, the biggest facilitators were as follows: belief that the modification works (27 to 37%), being recommended it (24 to 26%), and ease of use/performance (21 to 32%). Across modifications, the biggest barriers were difficulty of use (55%), lack of family/employer/social/community support (33%), and lack of awareness (32%). The data do not suggest discernible patterns of differences in barriers or facilitators by SES.

CONCLUSIONS

Greater emphasis should be placed on explaining to patients how environmental and behavioral modifications might mitigate DED. Employers and members of patients' support systems should be guided regarding how best to support patients in managing DED symptoms.

Screen time and pediatric headache: A scoping review of the literature

OBJECTIVE

The aim of this study was to summarize the evidence regarding screen use as a contributing factor in pediatric headache and migraine.

BACKGROUND

Screen exposure is often reported as a headache trigger, though there is no current consensus in terms of how screen type, duration, or frequency influences pediatric headache and the associated burden of disease.

METHODS

A systematic search in PubMed, Scopus, Cochrane Library, ProQuest Health and Medical Database, and Google Scholar was performed through November 2022 in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All English-language articles of pediatric patients aged ≤18 years evaluating screen use in relation to headache were included.

RESULTS

A total of 48 studies were included. Nearly all studies were cross-sectional and represented international samples. The strongest association between screen use and headache found was for duration of use, and computer use emerged as the most common device type related to headache. While there were mixed findings related to screen use and specific headache diagnosis, migraine appeared to confer a higher risk. Across studies, there were insufficient data to assess the impact of screen use on headache frequency or headache-related disability. Several studies demonstrated changes in screen use and headache patterns related to the COVID-19 pandemic and computer vision syndrome was commonly reported.

CONCLUSIONS

While there is preliminary evidence supporting possible associations between screen use and pediatric headache, there are several limitations in the present review including a lack of prospective and randomized controlled trials to better demonstrate causal relationships as well as methodological limitations with significant variability in how both headache and screen use are defined and measured. Future studies including real-time screen use and device monitoring are needed to better understand the influence of screen use behaviors on pediatric headache and to help further define best-use guidelines around these technologies.

Enhancing Ocular Surface in Dry Eye Disease Patients: A Clinical Evaluation of a Topical Formulation Containing Sesquiterpene Lactone Helenalin

The aim of this work was to assess the tolerability, safety, and efficacy of an ophthalmic topical formulation containing helenalin from Arnica montana and hyaluronic acid 0.4% (HA) in patients with mild-to-moderate Dry Eye Disease (DED) exhibiting positive Matrix Metalloproteinase 9 (MMP-9) test results. Tolerability and safety were evaluated in 24 healthy subjects. Participants were instructed to apply one drop of the formulation three times a day in the study eye, for 2 weeks, followed by a clinical follow-up of 21 days. Efficacy was studied in 48 DED patients randomized into Study (Group 1/receiving the studied formulation) or Control (Group 2/Receiving HA 0.4% eye lubricant) groups for 1 month. Assessments included an MMP-9 positivity test, conjunctival impression cytology (CIC), Ocular Surface Disease Index (OSDI), non-invasive film tear breakup time (NIBUT), non-invasive average breakup time (NIAvg-BUT), ocular surface staining, Schirmer's test, and meibomiography. A crossover design with an additional 1-month follow-up was applied to both groups. Healthy subjects receiving the studied formulation exhibited good tolerability and no adverse events. Regarding the efficacy study, Group 1 exhibited a statistically significant reduction in the MMP-9 positivity rate compared to Group 2 (p < 0.001). Both Group 1 and Group 2 exhibited substantial improvements in OSDI and NIBUT scores (p < 0.001). However, Group 1 demonstrated a significant improvement in NI-Avg-BUT and Schirmer's test scores (p < 0.001), whereas Group 2 did not (p > 0.05). Finally, after the crossover, the proportion of MMP-9-positive subjects in Group 1 increased from 25% to 91.6%, while Group 2 showed a significant decrease from 87.5% to 20.8%. Overall, the topical formulation containing sesquiterpene helenalin from Arnica montana and hyaluronic acid was well tolerated and exhibited a favorable safety profile. Our formulation reduces DED symptomatology and modulates the ocular surface inflammatory process; this is evidenced by the enhancement of CIC, the improvement of DED-related tear film status, and the reduction of the MMP-9 positivity rate.

Impact of Neurolens Use on the Quality of Life in Individuals With Headaches: A Randomized Double-Masked, Cross-Over Clinical Trial

Purpose

Vision-related disorders, such as refractive errors and binocular vision issues, can cause headaches. The current study evaluates the impact of Neurolens (NL) on individuals with headaches, assessed using the Headache Impact Test (HIT) questionnaire.

Methods

Subjects (18-60 years) with good stereoacuity and a HIT score of ≥56 points were enrolled. Each subject wore both control lens and NL for 30 ± 10 days each. The primary outcome of the study was to assess the difference in the HIT score between the two treatments.

Results

Of the subjects randomized, 88% (170/195) completed the study. Overall, subjects reported a greater improvement in HIT score improvement with NL compared with control (mean difference, -1.53 points; 95% confidence interval, -2.8 to -0.26; P = 0.01). In the subgroup with reduced NPC, subjects reported a larger improvement in HIT score improvement with NL but was not statistically significant (mean difference, -1.89 points; 95% confidence interval, -4.27 to -0.47; P = 0.11).

Conclusions

NL produced a statistically significant decrease in the impact of headaches on individuals' quality of life compared with placebo. Although the overall magnitude of the decrease was not clinically significant, a clinically meaningful improvement with NL cannot be ruled out with high certainty in the current study.

Translational Relevance

Headache is one of the most experienced symptoms by individuals worldwide with vision-related disorders being a primary reason. It is, therefore, critical to screen these disorders before providing a pharmacological intervention, which may have side effects. NL provides an objective way to diagnose and treat digital eyestrain-related headaches.

Interventions for Dry Eye: An Overview of Systematic Reviews

Importance

Dry eye is a common ocular disease that can have substantial morbidity. Systematic reviews provide evidence for dry eye interventions and can be useful for patients, clinicians, and clinical guideline developers. Overviews of reviews use explicit and systematic methods to synthesize findings from multiple systematic reviews, but currently, there are no overviews of systematic reviews investigating interventions for dry eye.

Objective

To summarize the results of reliable systematic reviews of dry eye interventions and to highlight the evidence gaps identified.

Evidence Review

We searched the Cochrane Eyes and Vision US satellite database and included reliable systematic reviews evaluating dry eye interventions published from 2016 to 2022. We reported the proportion of systematic reviews that were reliable with reasons for unreliability. Critical and important outcomes from reliable systematic reviews were extracted and verified. Critical outcomes included dry eye-related patient-reported outcome measures. Results were synthesized from reliable systematic reviews to provide summaries of evidence for each intervention. Evidence for each intervention was defined as conclusive or inconclusive depending on whether high-certainty evidence across systematic reviews was available according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria and whether findings reached statistical or clinical significance. Recommendations were made for further research.

Findings

Within the Cochrane Eyes and Vision US satellite database, 138 potentially relevant systematic reviews were identified, 71 were considered eligible, and 26 (37%) were assessed as reliable. Among reliable systematic reviews, no conclusive evidence was identified for any dry eye intervention. Inconclusive evidence suggested that environmental modifications, dietary modifications, artificial tears and lubricants, punctal occlusion, intense pulsed light therapy, vectored thermal pulsation therapy (Lipiflow), topical corticosteroids, topical cyclosporine A, topical secretagogues, and autologous serum may be effective. Only unreliable systematic reviews evaluated lifitegrast, oral antibiotics, and moisture chamber devices.

Conclusions and Relevance

This overview of systematic reviews found some evidence that dry eye interventions may be effective, but no conclusive evidence was available. The conduct and reporting of most systematic reviews for dry eye interventions warrant improvement, and reliable systematic reviews are needed to evaluate lifitegrast, oral antibiotics, and moisture chamber devices.

Prevalence of computer vision syndrome: A systematic review and meta-analysis

PURPOSE

This review aimed to estimate the prevalence of computer vision syndrome (CVS) in the general population and subgroups.

METHODS

A search was conducted in the following the databases: PubMed, SCOPUS, EMBASE, and Web of Science until February 13, 2023. We included studies that assessed the prevalence of CVS in any population. The Joanna Briggs Institute's critical appraisal tool was used to evaluate the methodological quality. A meta-analysis of the prevalence of CVS was done using a random-effects model, assessing the sources of heterogeneity using subgroup and meta-regression analyses.

RESULTS

A total of 103 cross-sectional studies with 66 577 participants were included. The prevalence of CVS was 69.0% (95% CI: 62.3 to 75.3; I2: 99.7%), ranging from 12.1 to 97.3% across studies. Point prevalence was higher in women than in men (71.4 vs. 61.8%), university students (76.1%), Africa (71.2%), Asia (69.9%), contact lens wearers (73.1% vs. 63.8%) in studies conducted before the COVID-19 pandemic (72.8%), and in those that did not use the CVS-Q questionnaire (75.4%). In meta-regression, using the CVS-Q scale was associated with a lower prevalence of CVS.

CONCLUSION

Seven out of ten people suffer from CVS. Preventive strategies and interventions are needed to decrease the prevalence of this condition which can affect productivity and quality of life. Future studies should standardize a definition of CVS.

Plant bioactive compounds alleviate photoinduced retinal damage and asthenopia: Mechanisms, synergies, and bioavailability

The retina, an important tissue of the eye, is essential in visual transmission and sustaining adequate eyesight. However, oxidative stress and inflammatory reactions can harm retinal structure and function. Recent studies have demonstrated that exposure to light can induce oxidative stress and inflammatory reactions in retinal cells, thereby facilitating the progression of retinal damage-related diseases and asthenopia. Plant bioactive compounds such as anthocyanin, curcumin, resveratrol, lutein, zeaxanthin, epigallocatechin gallate, and quercetin are effective in alleviating retinal damage and asthenopia. Their strong oxidation resistance and unique chemical structure can prevent the retina from producing reactive oxygen species and regulating eye muscle relaxation, thus alleviating retinal damage and asthenopia. Additionally, the combination of these active ingredients produces a stronger antioxidant effect. Consequently, understanding the mechanism of retinal damage caused by light and the regulation mechanism of bioactive compounds can better protect the retina and reduce asthenopia.

Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adults

BACKGROUND

'Blue-light filtering', or 'blue-light blocking', spectacle lenses filter ultraviolet radiation and varying portions of short-wavelength visible light from reaching the eye. Various blue-light filtering lenses are commercially available. Some claims exist that they can improve visual performance with digital device use, provide retinal protection, and promote sleep quality. We investigated clinical trial evidence for these suggested effects, and considered any potential adverse effects.

OBJECTIVES

To assess the effects of blue-light filtering lenses compared with non-blue-light filtering lenses, for improving visual performance, providing macular protection, and improving sleep quality in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; containing the Cochrane Eyes and Vision Trials Register; 2022, Issue 3); Ovid MEDLINE; Ovid Embase; LILACS; the ISRCTN registry; ClinicalTrials.gov and WHO ICTRP, with no date or language restrictions. We last searched the electronic databases on 22 March 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), involving adult participants, where blue-light filtering spectacle lenses were compared with non-blue-light filtering spectacle lenses.

DATA COLLECTION AND ANALYSIS

Primary outcomes were the change in visual fatigue score and critical flicker-fusion frequency (CFF), as continuous outcomes, between baseline and one month of follow-up. Secondary outcomes included best-corrected visual acuity (BCVA), contrast sensitivity, discomfort glare, proportion of eyes with a pathological macular finding, colour discrimination, proportion of participants with reduced daytime alertness, serum melatonin levels, subjective sleep quality, and patient satisfaction with their visual performance. We evaluated findings related to ocular and systemic adverse effects. We followed standard Cochrane methods for data extraction and assessed risk of bias using the Cochrane Risk of Bias 1 (RoB 1) tool. We used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included 17 RCTs, with sample sizes ranging from five to 156 participants, and intervention follow-up periods from less than one day to five weeks. About half of included trials used a parallel-arm design; the rest adopted a cross-over design. A variety of participant characteristics was represented across the studies, ranging from healthy adults to individuals with mental health and sleep disorders. None of the studies had a low risk of bias in all seven Cochrane RoB 1 domains. We judged 65% of studies to have a high risk of bias due to outcome assessors not being masked (detection bias) and 59% to be at high risk of bias of performance bias as participants and personnel were not masked. Thirty-five per cent of studies were pre-registered on a trial registry. We did not perform meta-analyses for any of the outcome measures, due to lack of available quantitative data, heterogenous study populations, and differences in intervention follow-up periods. There may be no difference in subjective visual fatigue scores with blue-light filtering lenses compared to non-blue-light filtering lenses, at less than one week of follow-up (low-certainty evidence). One RCT reported no difference between intervention arms (mean difference (MD) 9.76 units (indicating worse symptoms), 95% confidence interval (CI) -33.95 to 53.47; 120 participants). Further, two studies (46 participants, combined) that measured visual fatigue scores reported no significant difference between intervention arms. There may be little to no difference in CFF with blue-light filtering lenses compared to non-blue-light filtering lenses, measured at less than one day of follow-up (low-certainty evidence). One study reported no significant difference between intervention arms (MD - 1.13 Hz lower (indicating poorer performance), 95% CI - 3.00 to 0.74; 120 participants). Another study reported a less negative change in CFF (indicating less visual fatigue) with high- compared to low-blue-light filtering and no blue-light filtering lenses. Compared to non-blue-light filtering lenses, there is probably little or no effect with blue-light filtering lenses on visual performance (BCVA) (MD 0.00 logMAR units, 95% CI -0.02 to 0.02; 1 study, 156 participants; moderate-certainty evidence), and unknown effects on daytime alertness (2 RCTs, 42 participants; very low-certainty evidence); uncertainty in these effects was due to lack of available data and the small number of studies reporting these outcomes. We do not know if blue-light filtering spectacle lenses are equivalent or superior to non-blue-light filtering spectacle lenses with respect to sleep quality (very low-certainty evidence). Inconsistent findings were evident across six RCTs (148 participants); three studies reported a significant improvement in sleep scores with blue-light filtering lenses compared to non-blue-light filtering lenses, and the other three studies reported no significant difference between intervention arms. We noted differences in the populations across studies and a lack of quantitative data. Device-related adverse effects were not consistently reported (9 RCTs, 333 participants; low-certainty evidence). Nine studies reported on adverse events related to study interventions; three studies described the occurrence of such events. Reported adverse events related to blue-light filtering lenses were infrequent, but included increased depressive symptoms, headache, discomfort wearing the glasses, and lower mood. Adverse events associated with non-blue-light filtering lenses were occasional hyperthymia, and discomfort wearing the spectacles. We were unable to determine whether blue-light filtering lenses affect contrast sensitivity, colour discrimination, discomfort glare, macular health, serum melatonin levels or overall patient visual satisfaction, compared to non-blue-light filtering lenses, as none of the studies evaluated these outcomes.

AUTHORS' CONCLUSIONS

This systematic review found that blue-light filtering spectacle lenses may not attenuate symptoms of eye strain with computer use, over a short-term follow-up period, compared to non-blue-light filtering lenses. Further, this review found no clinically meaningful difference in changes to CFF with blue-light filtering lenses compared to non-blue-light filtering lenses. Based on the current best available evidence, there is probably little or no effect of blue-light filtering lenses on BCVA compared with non-blue-light filtering lenses. Potential effects on sleep quality were also indeterminate, with included trials reporting mixed outcomes among heterogeneous study populations. There was no evidence from RCT publications relating to the outcomes of contrast sensitivity, colour discrimination, discomfort glare, macular health, serum melatonin levels, or overall patient visual satisfaction. Future high-quality randomised trials are required to define more clearly the effects of blue-light filtering lenses on visual performance, macular health and sleep, in adult populations.

Objective Evaluation of Active Interactions between the Operator and Display Screen Equipment Using an Innovative Acquisition System

The occupational risk of operators using display screen equipment (DSE) is usually evaluated according to the extent of time spent in active operator-DSE interactions. Risk assessment is based on activity data collected through questionnaires. We evaluated an original and innovative system that can objectively assess active operator-DSE interactions by collecting electrical impulses generated by the activation of mouse, keyboard and a camera that collects attentive eye-screen fixation. The main aim of this study was to evaluate the system's performance on an employee sample involved in the task of active reading and copying at a DSE workstation connected to the system. In the context of mandatory health surveillance at work, we enrolled 38 DSE operators with normal neuropsychological and eye assessments who were required to complete two predefined reading and writing tasks. The obtained results show that the system is able to collect activity data derived from operator-DSE interactions through screen fixation, keyboard tapping and mouse handling. In the copying task, the session duration as recorded by the system was highly related to the screen fixation time. In the copying task, mouse and keyboard activities were more strongly related to session duration than screen fixation. For the copying task, it was also possible to obtain individual profiles of operator-DSE interactions while performing the same standardized tasks. Collected data can allow an objective evaluation of active time spent by DSE operators at their workstations, thus allowing a more accurate occupational health risk assessment and management. Prospective analysis of individual operator-DSE interaction profiles can favor the setup of targeted preventive and organizational interventions from an of even wider worker wellbeing perspective.

Computer vision syndrome-related symptoms in presbyopic computer workers

PURPOSE

To evaluate the prevalence of computer vision syndrome (CVS)-related symptoms in a presbyopic population using the computer as the main work tool, as well as the relationship of CVS with the electronic device use habits and the ergonomic factors.

METHODS

A sample of 198 presbyopic participants (aged 45-65 years) who regularly work with a computer completed a customised questionnaire divided into: general demographics, optical correction commonly used and for work, habits of electronic devices use, ergonomic conditions during the working hours and CVS-related symptoms during work performance. A total of 10 CVS-related symptoms were questioned indicating the severity with which they occurred (0-4) and the median total symptom score (MTSS) was calculated as the sum of the symptoms.

RESULTS

The MTSS in this presbyopic population is 7 ± 5 symptoms. The most common symptoms reported by participants are dry eyes, tired eyes and difficulties in refocusing. MTSS is higher in women (p < 0.05), in laptop computer users (p < 0.05) and in teleworkers compared to office workers (p < 0.05). Regarding ergonomic conditions, MTSS is higher in participants who do not take breaks while working (p < 0.05), who have an inadequately lighting in the workspace (p < 0.05) and in the participants reporting neck (p < 0.01) or back pain (p < 0.001).

CONCLUSION

There is a relationship between CVS-related symptoms, the use of electronic devices and the ergonomic factors, which indicates the importance of adapting workplaces, especially for home-based teleworkers, and following basic visual ergonomics rules.

TFOS Lifestyle: Impact of the digital environment on the ocular surface

Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as "the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing". Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not 'diagnostic' of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts).

Is critical flicker-fusion frequency a valid measure of visual fatigue? A post-hoc analysis of a double-masked randomised controlled trial

PURPOSE

Critical flicker-fusion frequency (CFF) has been used in clinical studies as a measure of visual fatigue. We examine the correlation between CFF and subjective reports of visual fatigue in a group of symptomatic computer users, to consider whether CFF may be used as a surrogate measure of visual fatigue symptoms.

METHODS

We analysed data from a previous randomised controlled trial. One hundred and twenty adults, diagnosed with computer vision syndrome, had CFF and visual fatigue symptoms quantified before and after a visually demanding 2-h computer task. Symptoms were assessed using a questionnaire with nine subcomponents that summed to a total score of 900. CFF was measured using a two-interval forced-choice method, with the flicker rate altered by a computer-controlled staircase procedure. For our primary analysis, we determined Spearman correlation coefficients between post-task symptom scores and CFF, and between change from baseline symptom scores and CFF. We also used a bootstrap procedure to consider whether symptom score subcomponents were significantly (Bonferroni-corrected) different from overall scores with regard to their correlations with CFF.

RESULTS

Although visual fatigue symptom scores altered significantly post-task (mean change: 92 units; 95% confidence interval [CI]: 11 to 122), CFF did not (mean change -0.7 Hz; 95% CI: -1.7 to 0.3). There was no significant correlation between overall symptom scores and CFF, either for the post-task (r = -0.13; 95% CI: -0.31 to 0.05) or the change from baseline (r = -0.18; 95% CI: -0.35 to 0.01) analysis. Subcomponents of the symptom questionnaire did not show a significant correlation with CFF, either for the post-task or the change from baseline analysis.

CONCLUSIONS

We find that CFF is not a useful surrogate for symptoms of visual fatigue, given its low correlation with scores on a visual fatigue symptom questionnaire.

Spotlight on Digital Eye Strain

Digital Eye Strain (DES) is a clinical syndrome manifested with visual disturbances and/or ophthalmic dysfunction related to the usage of screen-enabled digital equipment. This term is gradually replacing the older term computer vision syndrome (CVS) that focused on the same symptoms found on personal computer users. DES is encountered more frequently during the past years due to the explosive increase in the usage of digital devices and subsequent increase in time in front of any screens. It presents with a series of atypical symptoms and signs stemming from asthenopia, dry eye syndrome, preexisting untreated vision issues and poor screen ergonomics. This review summarizes research data to date to determine whether the concept of DES has been conclusively defined and demarcated as a separate entity and if sufficient guidance is offered on professionals and the lay public. The maturity of the field, grouping of symptoms, examination techniques, treatment and prevention modalities are summarily presented.

Evaluation of the effectiveness of the Super Enhanced Single Vision Lens 01 (SESL01) in reducing symptoms of computer vision syndrome (CVS): A study protocol for a double-blind, two-arm parallel randomized controlled trial

BACKGROUND

The increased use of digital devices has implications for health and, particularly, the eyes, due to Computer Vision Syndrome (CVS). Millions of individuals of all ages are at risk of CVS, and its prevalence ranges from 25% to 93%. This trial will evaluate the effectiveness of the Super Enhanced Single Vision Lens 01 (SESL01) versus standard single vision lens in reducing symptoms of CVS assessed by the Computer Vision Syndrome Questionnaire (CVS-Q®) scores.

METHOD

A double-blind, two-arm parallel randomized controlled trial will be conducted at the University of Central Lancashire, Preston (UK), recruiting students and staff with CVS-Q score ≥ 6. A 1:1 randomization and a sample size of 300 participants will be sufficient to detect a 2-point difference in the CVS-Q score between the intervention and control groups with an alpha of 5%, two-sided, allowing for a dropout of 10%. The control group will use standard single vision lenses, and the intervention group SESL01. The primary outcome to week 14 will be the difference in the CVS-Q score between SESL01 and standard single vision lenses. Secondary outcomes include the percentage of participants with CVS-Q score < 6 (no symptoms) and CVS-Q score ≥ 6 (symptoms) in the SESL01 and the standard single vision group at weeks 6, 10 and 14; the percentage of participants in each group with a total CVS-Q score < 6, 6-12, 13-19, and ≥ 20 at weeks 6, 10 and 14. The primary analysis will be the intention to treat.

DISCUSSION

Findings may inform decisions about adopting the SESL01 lenses to reduce CVS.

TRIAL REGISTRATION

clinicaltrial.gov identifier: NCT05545878. Registered: Sept. 19, 2022.

Prevalence and risk factors of computer vision syndrome-assessed in office workers by a validated questionnaire

Background

Computer vision syndrome (CVS) is a common occupational health problem, but its clinical definition, prevalence and risk factors are not well defined. In general, non-validated diagnostic instruments have been used to assess its prevalence. For this reason, the aim of this study is to estimate the prevalence and potential risk factors for CVS using a validated questionnaire.

Methods

A cross-sectional study (n = 238) was carried out in Italian office workers using digital devices. All participants responded to an anamnesis, a digital exposure questionnaire, and the validated Italian version of the Computer Vision Syndrome Questionnaire. A battery of 3 ocular surface and tear ophthalmic tests (break-up time, BUT), Schirmer II and corneal staining) was performed.

Results

The mean age (±SD) was 45.55 (11.02) years, 64.3% were female. 71.4% wore glasses to work, whose design was monofocal (for distance) in 47.6%, monofocal (for near) in 26.5%, general progressive in 16.5% and occupational progressive in 8.8% of cases. 35.7% used digital devices >6 hours/day in the workplace. The prevalence of CVS was 67.2%. In the multivariate model, female sex (aOR: 3.17; 95% CI [1.75-5.73]), the use of digital devices >6 hours/day at workplace (aOR: 2.07; 95% CI [1.09-3.95]) and the use of optical correction at work (aOR: 2.69; 95% CI [1.43-5.08]) significantly increased the odds of CVS. Association was observed between presenting CVS and having abnormal BUT (χ2 = 0.017).

Conclusions

The prevalence of CVS in Italian office workers, especially among females, was high. Intensive use of digital devices at work (>6 hours/day) and the use of optical correction at work significantly increased the odds of CVS. There is an association between poor tear stability and CVS. Further research is needed on the influence of wearing optical correction on CVS. The use of a validated questionnaire in health surveillance of digital workers is strongly recommended.