Computer vision syndrome prevalence according to individual and video display terminal exposure characteristics in Spanish university students

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.

Ocular surface changes following computer use in post-LASIK patients

PURPOSE

To assess the impact of computer use on the ocular surface of individuals after laser in situ keratomileusis (LASIK).

METHODS

The dry eye symptoms and ocular surface of 18 post-LASIK young individuals and 18 controls were evaluated before and after performing a 30-min task on a computer without (Visit 1) and with (Visit 2) initial instillation of artificial tears. Symptoms were assessed using the Ocular Surface Disease Index (OSDI), Symptom Assessment in Dry Eye questionnaire version two (SANDE II) and Computer Vision Syndrome Questionnaire (CVS-Q). The ocular surface was assessed by measuring corneal higher order aberrations, tear meniscus height (TMH), conjunctival redness, blink rate and incomplete blinking, lipid layer thickness (LLT) and non-invasive keratograph break-up time (NIKBUT).

RESULTS

SANDE II scores were >0 after the computer task in both groups (p ≤ 0.01). SANDE II and CVS-Q scores did not differ between LASIK and controls (p ≥ 0.43). Greater bulbar-temporal conjunctival redness, TMH and LLT and shorter NIKBUT were found after computer use in the LASIK group (p ≤ 0.04), whereas no changes were observed in the controls (p ≥ 0.20). Lower SANDE II and CVS-Q scores were reported at Visit 2 compared with Visit 1 in both groups (p ≤ 0.01). Likewise, no worsening of dry eye signs was observed at Visit 2 (p ≥ 0.11).

CONCLUSIONS

Ocular symptoms reported during computer use were comparable between the groups. However, a worsening of dry eye signs was mostly observed in post-LASIK individuals. The instillation of artificial tears was effective in preventing the effects of computer use on the ocular surface in post-LASIK patients.

Computer vision syndrome among Sudanese medical students: a growing medical issue in the digital world

Computer vision syndrome (CVS) refers to a set of eye-related symptoms that arise from prolonged computer usage. A survey was conducted to investigate the demographic characteristics, factors contributing to, and preventive measures against CVS. Out of 159 participants, 31.0% experienced seven or more symptoms, indicating a notable prevalence. The study found no significant correlation between age or academic years and CVS occurrence (P values of 0.481 and 0.392, respectively). However, gender exhibited a statistically significant relationship, with females students showing a higher prevalence than males (P=0.018; τ=0.105*). Notably, the distance from the screen had a highly significant inverse correlation with CVS occurrence (P=0.000; τ=-0.207**), indicating that greater distance reduced the risk. Additionally, using a screen filter (P=0.000; τ=0.184**) and adjusting screen brightness (P=0.017; τ=0.101*) were associated with CVS occurrence. Among preventive measures, only the use of an anti-glare screen showed a significant association with reducing CVS risk (P=0.018; τ=-0.099*). Given these findings, raising awareness about CVS among medical students is recommended, especially as curricula in medical colleges evolve.

Visual display terminal syndrome and its associated factors among university students during the COVID-19 pandemic

BACKGROUND

Ever since the start of the coronavirus disease 2019 (COVID-19) pandemic, students have been spending an increasingly longer time staring at electrical devices to take online courses.

OBJECTIVE

This study aimed to investigate the effect of the virtual class environment on eye and musculoskeletal problems in university students during the COVID-19 pandemic.

METHODS

A total of 365 university students were enrolled in this study. They completed an online survey to examine the effects of online learning on eye and musculoskeletal health during the COVID-19 pandemic. The questionnaires consisted of four sections: demographic and general information, environmental and work factors, device-related factors, and visual display terminal syndrome (VDTS).

RESULTS

Participants have been taking online classes of 14.5 hours per week during the COVID-19 pandemic. They reported the mean daily usage of digital devices of 4.8±2.2 hours before the pandemic but this increased to 8.1±2.9 during the pandemic. Eye fatigue and neck, shoulder, and back pain have also been reported. The mean VDTS score was significantly influenced by gender, obesity, daily exercise, regular breaks, wear of blue light-blocking glasses, daily hours of electronic device use, and illumination of room.

CONCLUSION

The results of this study showed that university students taking online classes suffered more from VDTS, especially in eye fatigue and neck, lower back, and shoulder pain during COVID-19 pandemic than prior. This study suggests that it is necessary to take breaks in online classes and regularly provide appropriate eye exercise and physical activity to prevent VDTS.

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.

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.

The effects of breaks on digital eye strain, dry eye and binocular vision: Testing the 20-20-20 rule

PURPOSE

To evaluate the benefits on the eyes of taking breaks based on the 20-20-20 rule.

METHODS

Bespoke computer software using the laptop webcam to assess user breaks, eye gaze and blinking, and emitting personalized reminders of breaks based on the 20-20-20 rule, was downloaded onto the laptops of 29 symptomatic computer users. Digital eye strain (DES), binocular vision and dry eye were assessed before and after two weeks of using the reminders and one week after the discontinuation of the strategy. Binocular measurements included visual acuity, accommodative posture, stereopsis, fixation disparity, ocular alignment, accommodative facility, positive/negative vergences and near point of convergence. Symptoms were evaluated using the computer vision syndrome questionnaire, ocular surface disease index (OSDI), and symptom assessment in dry eye questionnaire (SANDE) versions one and two. Dry eye signs were assessed by measuring tear meniscus height, conjunctival redness, blink rate and incomplete blinking, lipid layer thickness, non-invasive keratograph break-up time, corneal and conjunctival staining and lid wiper epitheliopathy.

RESULTS

A decrease in the duration of computer work and the duration of breaks, along with an increase in the number of breaks taken per day was observed as a result of the 20-20-20 rule reminders (p ≤ 0.015). No changes on any binocular parameter were observed after the management period (p ≥ 0.051), except for an increase in accommodative facility (p = 0.010). Dry eye symptoms and DES decreased with the rule reminders (p ≤ 0.045), although this improvement was not maintained one week after discontinuation (p > 0.05). No changes on any ocular surface and tear film parameter were observed with the rule reminders (p ≥ 0.089).

CONCLUSIONS

The 20-20-20 rule is an effective strategy for reducing DES and dry eye symptoms, although 2 weeks was not enough to considerably improve binocular vision or dry eye signs.

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).

Digital Eye Strain among Peruvian Nursing Students: Prevalence and Associated Factors

There has been a high prevalence of digital eye strain (DES) among students who have received distance-learning lessons due to COVID-19. However, in low- and middle-income countries, there are few studies that have analyzed its associated factors. This study aimed to determine the prevalence of DES and its associated factors among nursing students during COVID-19 distance learning. This was a cross-sectional analytical study conducted between May and June 2021 in six Peruvian universities. The sample comprised 796 nursing students. DES was measured using the Computer Vision Syndrome Questionnaire (CVS-Q). A bivariate logistic regression analysis was performed. DES was found in 87.6% of nursing students. Sitting upright (OR, 0.47; 95% IC, 0.30-0.74), using electronic devices for more than four hours a day (OR, 1.73; 95% IC, 1.02-2.86), not following the 20-20-20 rule (OR, 2.60; 95% IC, 1.25-5.20), having the screen brightness very high (OR, 3.36; 95% IC, 1.23-11.8), and not wearing glasses (OR, 0.59; 95% IC, 0.37-0.93) are factors associated with DES. The prevalence of DES among nursing students is high. Improving the ergonomics of study environments, reducing the time of exposure to electronic devices, adjusting the screen brightness, and taking eye-care measures are key to controlling computer vision syndrome in virtual learning.

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

Although computer vision syndromes are becoming a major public health concern, less emphasis is given to them, particularly in developing countries. There are primary studies on different continents; however, there are inconsistent findings in prevalence among the primary studies. Therefore, this systematic review and meta-analysis aimed to estimate the pooled prevalence of computer vision syndrome. In this study, the review was developed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Online electronic databases, including PubMed/Medline, CINAHL, and Google Scholar, were used to retrieve published and unpublished studies. The study was conducted from December 1 to April 9/2022. Study selection, quality assessment, and data extraction were performed independently by two authors. Quality assessment of the studies was performed using the Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument tool. Heterogeneity was assessed using the statistical test I². STATA 14 software was used for statistical analysis. A total of 7,35 studies were retrieved, and 45 studies were included in the final meta-analysis. The pooled prevalence of computer vision syndrome was 66% (95% CI: 59, 74). Subgroup analysis based on country was highest in Pakistan (97%, 95% CI: 96, 98) and lowest in Japan (12%, 95% CI: 9, 15). Subgroup analysis based on country showed that studies in Saudi Arabia (I² = 99.41%, p value < 0.001), Ethiopia (I² = 72.6%, p value < 0.001), and India (I² = 98.04%, p value < 0.001) had significant heterogeneity. In the sensitivity analysis, no single study unduly influenced the overall effect estimate. Nearly two in three participants had computer vision syndrome. Thus, preventive practice strategic activities for computer vision syndrome are important interventions.

Computer vision syndrome and its determinants: A systematic review and meta-analysis

Objective:

Computer vision syndromes are becoming a major public health concern. Inconsistent findings existed on computer vision syndrome. This systematic review and meta-analysis aimed to estimate the pooled prevalence of computer vision syndrome and identify its determinants.

Methods:

In this study, the review was developed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Online electronic databases, including PubMed/Medline, CINAHL, and Google Scholar, were used to retrieve studies from 1 December to 9 April 2022. Quality assessment of the studies was performed using the JBI-MAStARI. RevMan and STATA 14 software were used for statistical analysis.

Result:

A total of 725 studies were retrieved, and 49 studies were included. The pooled prevalence of computer vision syndrome was 66% (95%, Confidence interval: 59, 74). Being female (Odd Ratio = 1.74, 95% Confidence interval [1.2, 2.53]), improper body posturing while using electronic devices (Odd Ratio = 2.65, 95% Confidence interval [1.7, 4.12]), use of electronic devices out of work (Odd Ratio = 1.66, 95% CI [1.15, 2.39]), no habit of taking breaks (Odd Ratio = 2.24, 95% Confidence interval [1.13, 4.44]), long duration of visual display terminal use (Odd Ratio = 2.02, 95% Confidence interval [1.08, 3.77]), short distance screen (Odd Ratio = 4.24, 95% Confidence interval [2.33, 7.71]), and general ergonomic practice (Odd Ratio = 3.87, 95% Confidence interval [2.18, 6.86]) were associated with increased odds of computer vision syndrome. However, good knowledge (Odd Ratio = 4.04, 95% Confidence interval [2.75, 5.94]) of computer vision syndrome was associated with decreased odds of computer vision syndrome.

Conclusion:

Nearly two in three participants had computer vision syndrome. Being female, improper body posturing, use of electronics devices out of work, no habit of taking a break, long-hour duration of visual display terminal use, short-distance screen, and general ergonomic practice were associated with increased odds of computer vision syndrome.

Concurrent Rising of Dry Eye and Eye Strain Symptoms Among University Students During the COVID-19 Pandemic Era: A Cross-Sectional Study

PURPOSE

Students spend extended hours using electronic devices due to online teaching. Digital eye strain (DES) and dry eye disease (DED) symptoms are both associated with prolonged screen exposure time and may co-occur. This study aimed to evaluate the correlation between DES and DED symptoms and determine the prevalence of DED according to the severity of DES.

PATIENTS AND METHODS

This cross-sectional study was conducted among international students in Chinese universities. The survey was built using Wenjuan Mini Program and distributed using the WeChat platform. The questionnaire assessed participants' screen exposure, the 20-20-20 rule, ED practices, and DED awareness. Computer Vision Syndrome Questionnaire (CVS-Q) and Dry Eye Questionnaire (DEQ-5) were used to diagnose DES and DED symptoms, respectively.

RESULTS

498 students completed the survey, but 452 were considered for the study. Predictors of DES and DED symptoms were conjunctivitis, eye allergy, glares, tired eye, neck pain, back pain, PhD students, and daily spending > 9h on screen (P < 0.05 for all). We observed that an increase in DES scores also exponentially increases DED scores. Among students diagnosed with DES symptoms, 26.5% had mild to moderate DED symptoms, and 8.2% had severe DED symptoms. In contrast, only 8.4% and 0.9% of those with asymptomatic DES had mild to moderate and severe DED symptoms, respectively (P < 0.000). A strong and significant positive correlation (r = 0.695, P < 0.000) between DES and DED scores was found.

CONCLUSION

We found an extremely high prevalence of DES and DED symptoms compared to the previous studies with a similar population group. We believe that the prevalence of DED may be underestimated in the young population. Training about proper ED practices is mandatory to prevent these deleterious ocular surface conditions.

Dry Eye-Related Risk Factors for Digital Eye Strain

OBJECTIVES

To evaluate dry eye-related lifestyle and demographic factors associated with digital eye strain (DES).

METHODS

An anonymous online survey was conducted in 851 university students. Participants were classified into DES (computer vision syndrome questionnaire [CVS-Q]≥6) or non-DES (CVS-Q<6). Respondents completed three dry eye questionnaires (Ocular Surface Disease Index [OSDI]; 5-item Dry Eye Questionnaire [DEQ-5]; 8-item Contact Lens Dry Eye Questionnaire) and were surveyed on dry eye risk factors contemplated by the Tear Film and Ocular Surface Society Dry Eye Workshop II.

RESULTS

Six hundred twenty-eight participants were classified into the group with DES and 222 into the group without DES. Participants with DES slept fewer hours, spent more hours indoors with air conditioning, drank more caffeinated beverages, used the computer for longer periods, reported poorer health quality, and obtained a higher score in all questionnaires (P<0.025). A higher proportion of the participants were female, had several health disorders, and took several medications associated with dry eye (P<0.029). Multivariate logistic regression analysis revealed that stress (P=0.035), contact lens wear (P=0.011), hours of computer use per day (P=0.010), migraine headaches (P=0.013), and a higher OSDI (P<0.001) and DEQ-5 score (P<0.001) were associated with DES.

CONCLUSIONS

Several dry eye-related risk factors and health conditions are associated with suffering from DES. Clinicians should acknowledge the relevance of triaging questions and dry eye disease risk factors when dealing with patients who view screens for extended periods.

Computer Visual Syndrome in Medical Students From a Private University in Paraguay: A Survey Study

Purpose

To determine the prevalence and factors associated with computer vision syndrome in medical students at a private university in Paraguay.

Methods

A survey study was conducted in 2021 in a sample of 228 medical students from the Universidad del Pacífico, Paraguay. The dependent variable was CVS, measured with the Computer Visual Syndrome Questionnaire (CVS-Q). Its association with covariates (hours of daily use of notebook, smartphone, tablet and PC, taking breaks when using equipment, use of preventive visual measures, use of glasses, etc.) was examined.

Results

The mean age was 22.3 years and 71.5% were women. CVS was present in 82.5% of participants. Higher prevalence of CVS was associated with wearing a framed lens (PR = 1.11, 95% CI: 1.03–1.20). In contrast, taking a break when using electronic equipment at least every 20 min and every 1 h reduced 7% (PR = 0.93, 95% CI: 0.87–0.99) and 6% (PR = 0.94, 95% CI: 0.89–0.99) the prevalence of CVS, respectively.

Conclusion

Eight out of 10 students experienced CVS during the COVID-19 pandemic. The use of framed lenses increased the presence of CVS, while taking breaks when using electronic equipment at least every 20 min and every 1 h reduced CVS.

Effects of digital devices and online learning on computer vision syndrome in students during the COVID-19 era: an online questionnaire study

PURPOSE

Computer vision syndrome (CVS) describes a group of eye and vision-related problems that result from prolonged digital device use. This study aims to assess the prevalence and associated factors of CVS among students during the lockdown resulting from the COVID-19 pandemic.

METHODS

A cross-sectional, online, questionnaire-based study performed among high school students in Thailand.

RESULTS

A total of 2476 students, with mean age of 15.52±1.66 years, were included in this study. The mean number of hours of digital device use per day (10.53±2.99) increased during the COVID-19 pandemic compared with before its advent (6.13±2.8). The mean number of hours of online learning was 7.03±2.06 hours per day during the pandemic. CVS was found in 70.1% of students, and its severity correlated with both the number of hours of online learning and the total number of hours of digital device usage (p<0.001). Multiple logistic regression analysis revealed that the factors associated with CVS included age ≤15 years (adjusted OR (AOR)=2.17), overall digital device usage >6 hours per day (AOR=1.91), online learning >5 hours per day (AOR=4.99), multiple digital device usage (AOR=2.15), refractive errors (AOR=2.89), presence of back pain (AOR=2.06) and presence of neck pain (AOR=2.36).

CONCLUSIONS

The number of hours of digital device usage increased during lockdown. Over 70% of children had CVS, whose associated factors, including hours of digital device usage, hours of online learning, ergonomics and refractive errors, should be adjusted to decrease the risk of acquiring this condition. Online learning will remain, along with CVS, after this pandemic, and we hope our research will be taken into account in remodelling our education system accordingly.

Fatigue Assessment of Sedentary Office Workers using Smart Phones: A Preliminary Study

BACKGROUND

Smartphone-based gait assessment provides a novel method to evaluate fatigue.

OBJECTIVE

This study aimed to examine self-reported fatigue and gait parameters recorded using a smartphone before and after an 8-hour work day in bank workers, and identify the relationship between self-reported fatigue and gait parameters.

METHODS

100 bank workers (20-45 years) were tested before and after an 8-hour work day using a reaction time test, self-reported fatigue scale, and gait test. Spearman correlation coefficient analysis and partial least squares regression were used to identify the relationship between self-reported fatigue and gait parameters.

RESULTS

Reaction time and self-reported fatigue increased significantly after work. Gait parameters (step frequency, minimum acceleration, acceleration root mean square, step regularity, and step counts) decreased; step time and step time variability increased significantly (p < 0.05). We found a significant correlation between Δwork engagement (delta: Δ) and Δstep frequency (r = -0.20, p < 0.05), Δwork engagement and Δstep time (r = 0.21, p < 0.05), and Δwork tasks and Δstep symmetry (r = -0.20, p < 0.05).

DISCUSSION

This study suggests that step frequency, step time and step symmetry measured using a smartphone have the potential to be used as predictors of work fatigue.

Immediate Ocular Changes After Light-Emitting Diode Displays Exposure-A Preliminary Study

Purpose

Computer vision syndrome (CVS) is one of the most frequently encountered problems among video display terminals (VDT) users, but little is known regarding the short-term effect after exposure to light-emitting diodes (LED). The purpose of this study was to determine if short-term exposure to LED leads to changes in corrected distance visual acuity (CDVA), lipid layer thickness (LLT), blink rates, partial blink ratio, and computer vision syndrome questionnaire (CVS-Q) score.

Design

Prospective, cross-sectional study.

Methods

In this study, participants were recruited at the National Cheng-Kung University Hospital, a tertiary referral center in southern Taiwan, for examination. Participants were asked to complete the CVS-Q and undergo a series of ocular examinations, including CDVA, LLT, blink rates and partial blink ratio before and after watching an LED display for 15 min. Main Outcome Measures were changes in CDVA, LLT, blink rates, partial blink ratio, and CVS-Q measurements.

Results

In total, 120 eyes from 60 participants (mean age: 35.7 ± 9.4 years) were included; 31 participants were men (51.7%), and 29 were women (48.3%). The CDVA, LLT, blink rates, and partial blink ratio did not change after watching the LED display. The CVS-Q score significantly improved after short-term LED exposure (P < 0.001). A subgroup analysis of subjects with a baseline LLT of <60 nm or ≥60 nm determined that LLT significantly decreased in individuals with a baseline LLT of ≥60 nm (P = 0.016).

Conclusion

Short-term use of LED displays reduced LLT in individuals with a baseline LLT of ≥60 nm, despite the visual symptoms of CVS improved subjectively. Therefore, digital device users should be aware of the potential negative effects of LED exposure on the eyes.

Ocular surface predisposing factors for digital display-induced dry eye

CLINICAL RELEVANCE

The use of digital displays is recognised as a consistent risk factor for dry eye disease.

BACKGROUND

To identify ocular parameters contributing to the impact of computer use on dry eye.

METHODS

The ocular surface of 82 undergraduate students with a mean age of 22.8 ± 2.1 years was assessed at baseline and after reading on a computer for 30 minutes. Measurements included the ocular surface disease index (OSDI) questionnaire, 5-item dry eye questionnaire (DEQ-5), tear meniscus height, non-invasive keratograph break-up time (NIKBUT), conjunctival bulbar redness, meibomian gland dropout percentage, spontaneous blink rate and percentage of incomplete blinks. Multiple linear regressions and generalised linear mixed models were conducted to explore the associations between baseline parameters and pre-task - post-task differences and to predict the impact of computer use, respectively.

RESULTS

Greater dry eye symptoms (p < 0.0005), higher tear meniscus height and conjunctival bulbar redness (p < 0.0005 and p = 0.012, respectively) and shorter NIKBUT (p = 0.03) were obtained after reading on the computer for 30 minutes. The baseline score obtained with the OSDI and DEQ-5 was positively associated with the increase in symptoms with computer use (p < 0.0005), while the change in conjunctival redness and pre-task NIKBUT were associated with the change in NIKBUT (p ≤ 0.005). No ocular surface parameter revealed an association with tear meniscus height changes. Having a positive OSDI score at baseline increased the odds of painful and sore eyes (p = 0.012), while a higher pre-task NIKBUT increased the odds of a reduction in tear stability (p = 0.038).

CONCLUSIONS

Participants with greater dry eye symptoms were more likely to experience a greater increase in symptomatology with computer operation, while the participants with longer NIKBUT and greater conjunctival redness were more likely to suffer a greater reduction in tear stability.

Computer Vision Syndrome During SARS-CoV-2 Outbreak in University Students: A Comparison Between Online Courses and Classroom Lectures

Purpose: To compare the prevalence of computer vision syndrome in university students of different teaching modes during the SARS-CoV-2 outbreak period. Methods: A cross-sectional survey study using the validated Computer Vision Syndrome Questionnaire in Chinese medical students of Sichuan University who took classroom lectures and the same-grade foreign students from a Bachelor of Medicine and Bachelor of Surgery (MBBS) program who took online lectures with similar schedules. Results: A total of 137 responses from 63 Chinese students and 74 MBBS students were obtained. The highest frequency of digital screen time was 7-9 h (43.24%, 32/74) for MBBS students and 2-4 h (46.03%, 29/63) for Chinese students. The prevalence of computer vision syndrome among Chinese students and MBBS students were 50.79% and 74.32%, respectively (P = 0.004). The average numbers of reported symptoms were 5.00 ± 2.17 in Chinese students and 5.91 ± 1.90 in MBBS students (P = 0.01). The three most highly reported symptoms were "heavy eyelids" (53.97%), "dryness" (50.79%), and "feeling of a foreign body" (46.03%) in Chinese students and "dryness" (72.97%), "feeling of a foreign body" (62.16%), and "heavy eyelids" (58.11%) in MBBS students. The sum grades of computer vision syndrome had a moderate positive correlation with screen time (Spearman's correlation coefficient = 0.386, P < 0.001). The grades of symptoms of "feeling of a foreign body," "heavy eyelids," and "dryness" showed a weak positive correlation with screen time (Spearman's correlation coefficients were 0.220, 0.205, and 0.230, respectively). Conclusion: Online study may contribute to the prevalence of computer vision syndrome among university students.

Health Issues with Learning to Use Smart Devices in the Digital Age: Using a Grounded Theory Approach

The Korean government has announced a plan for a national policy to deliver smart education among all students. As a result, many people are worried about the possible health-related adverse effects. This qualitative study aimed at analyzing health issues related to middle school students who learn by using smart devices using the grounded theory approach. We conducted in-depth interviews with 30 students at four middle schools who used smart devices for more than a year. The analysis of this research data was based on the constant comparative method, using grounded theory as a theoretical framework. The data analysis revealed many concepts in 28 subcategories and 13 categories related to smart learning health issues, with the central phenomenon being experience with health problems. Students' health-related experiences were classified as physical or psychosocial symptoms. Adverse health effects related to smart learning were related to unsafe smart learning behavior and an inefficient smart learning environment. The consequences appeared to be the formation of diverse digital habits through the ambivalent use of smart devices and differences in ability to control health problems. Our findings suggest that students can form ideal habits for using smart devices if their health issues are well monitored and managed.