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.

Computer vision syndrome and associated factors in university students and teachers in Nampula, Mozambique.

BACKGROUND: Computer Vision Syndrome (CVS) is a complex of eye and visual problems that arise while using a computer or other Video Display Terminal (DVT). With the advent of the COVID-19 pandemic, the use of these DVTs has become indispensable in the lives of students and teachers. This study aims to identify the prevalence of CVS and associated factors in students and teachers at Lúrio University, in Nampula, during the pandemic period. METHODS: This is a cross-sectional study, carried out between November 2020 and March 2021. The validated CVS questionnaire (CVS-Q) and another semi-structured questionnaire on ergonomic risk factors were applied. Odds ratios (OR) and adjusted odds ratios (aOR) were calculated to measure the association between CVS and computer use conditions. RESULTS: The prevalence of CVS was 76.6%, and the female gender, age ≤ 20 years, levels I, II, III of course, lack of knowledge about ergonomics, use the computer to study, use more than 6 hours daily, absence of anti-reflex treatment, use of other devices and sitting in an inappropriate chair were risk factors for the occurrence of CVS, while being a teacher was a protective factor. CONCLUSION: The prevalence of CVS found in this study was high, due to several factors, especially not using ergonomic principles when using computers and other DVTs. There is a need to adopt intervention strategies focused on the most vulnerable groups such as women, age group ≤20 years and students, especially at the first year level, right after entering the University.

Computer vision syndrome among students during remote learning periods: harnessing digital solutions for clear vision.

Aim: This study aimed to assess the prevalence of Computer Vision Syndrome (CVS) among children and adolescents in Qatar during the period of remote learning and explore the associated factors and discuss some digital health remedies that might reduce the risk. Methods: We conducted an analytical cross-sectional study between June and August 2022 by collecting data via telephone interviews with parents of selected students utilizing the Computer Vision Syndrome Questionnaire (CVS-Q). Results: We completed 1,546 interviews. The mean age of the students was (11 ± 2), male: female ratio was almost 1:1. About one quarter (368, 23.8%) of parents reported a previous diagnosis of visual disturbances among their children with over 88% of them wearing eyeglasses or medical contact lenses. The prevalence of CVS in our sample was about 8% (95%CI: 6.8-9.6). Mother's employment, having positive history of visual disturbances, and excess screen time were found to be significant predictors of CVS. Conclusion: Health care providers in collaboration with teachers should provide parents with evidence-based strategies to prevent or minimize the digital eye strain among students. In the landscape of remote learning, the implementation of digital remedies emerges as a proactive approach to mitigate the risk of digital eye strain.

The 20/20/20 rule: Practicing pattern and associations with asthenopic symptoms.

Purpose: The present work style and lifestyle have increased the digital device use. Therefore, an increase in digital eyestrain is to be expected. We undertook a survey during coronavirus disease 2019 (COVID-19) pandemic to investigate the practice of 20/20/20 rule and its association with digital device use and asthenopic symptoms. While this rule is commonly advised, little is known about its validity. Methods: An online survey form was disseminated through social media and emails. The questions for eye-related symptoms were similar to the convergence insufficiency symptom survey (CISS). Participants with age ≥5 years were included, with parents completing the survey for children (≤16 years). Results: A total of 432 participants (mean ± standard deviation [SD]: 26.06 ± 13.92 years) were enrolled, of which 125 responses were for children. The 20/20/20 rule was practiced only by 34% of the participants either regularly (n = 38) or occasionally (n = 109). Those who had complaints of burning sensation and headache tended to practice this rule. Among adult participants, more females (47%) practiced this rule when compared to males (23%). Also, adult females significantly (P = 0.04) had more symptoms score when compared to males. In children, no such gender difference was found. Conclusion: Only one-third of participants practice the 20/20/20 rule at least occasionally. More number of adult females being symptomatic and practicing in greater number could be due to higher prevalence of dry eye condition in females. While the symptom of burning sensation could be related to dry eye, that of headache could be related to refractive error or binocular vision dysfunctions.

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.

Asthenopia prevalence and vision impairment severity among students attending online classes in low-income areas of western China during the COVID-19 pandemic.

INTRODUCTION: This study explored the impact of online learning during the coronavirus disease 2019 (COVID-19) pandemic on asthenopia and vision impairment in students, with the aim of establishing a theoretical basis for preventive approaches to vision health. METHODS: This balanced panel study enrolled students from western rural China. Participant information was collected before and during the COVID-19 pandemic via questionnaires administered at local vision care centres, along with clinical assessments of visual acuity. Paired t tests and fixed-effects models were used to analyse pandemic-related differences in visual status. RESULTS: In total, 128 students were included (mean age before pandemic, 11.82 ± 1.46 years). The mean total screen time was 3.22 ± 2.90 hours per day during the pandemic, whereas it was 1.97 ± 1.90 hours per day in the pre-pandemic period (P<0.001). Asthenopia prevalence was 55% (71/128) during the pandemic, and the mean visual acuity was 0.81 ± 0.30 logarithm of the minimum angle of resolution; these findings indicated increasing vision impairment, compared with the pre-pandemic period (both P<0.001). Notably, asthenopia prevalence increased by two- to three-fold, compared with the pre-pandemic period. An increase in screen time while learning was associated with an increase in asthenopia prevalence (P=0.034). CONCLUSION: During the COVID-19 pandemic, students spent more time on online classes, leading to worse visual acuity and vision health. Students in this study reported a significant increase in screen time, which was associated with increasing asthenopia prevalence and worse vision impairment. Further research is needed regarding the link between online classes and vision problems.

Dry eye symptoms and digital eyestrain - Emerging epidemics among university students due to online curriculum amid the COVID-19 pandemic. A cross-sectional study.

Purpose: Increased screen time has been a major concern among the students who have adopted the online curriculum amid the pandemic. The study was conducted to shed light on the changing trends of symptoms pertaining to dry eye disease and digital eyestrain due to the online curriculum and its negative implications on the ocular health of students. Methods: A cross-sectional study was conducted among students of Manipal Academy of Higher Education who are currently following the E-learning curriculum amid the COVID-19 pandemic the participants were surveyed using a pre-validated structured questionnaire. Results: The mean age of study participants was 23.33 ± 4.604 years. In total, 97.9% (321/352) of the respondents experienced at least three symptoms associated with the usage of digital devices. 88.1% of the participants were exposed to an average screen time of more than 4 hours per day. An increased number of hours of digital device usage was found to be associated with higher total symptom scores (P = 0.04). The total symptom scores were found to be considerably higher for those with continuous contact with the screen (P = 0.02). Headache (69.9%, n = 246) is the most commonly reported symptom followed by neck pain (65.3%, n = 230), tearing (44.6%, n = 157), eye pain (40.9%, n = 144), and burning sensation (40.1%, n = 141). Conclusion: This study highlights a tremendous increase in the prevalence of symptoms related to dry eye and digital eyestrain among students attending online classes during the COVID-19 pandemic. Eye care professionals need to be aware of this emerging public health threat and the appropriate measures for its prevention.

Computer Vision Syndrome: An Ophthalmic Pathology of the Modern Era.

Digital device usage has increased significantly in last decade among all age groups, both for educational and recreational purposes. Computer vision syndrome (CVS), also known as digital eye strain (DES), represents a range of ocular, musculoskeletal, and behavioral conditions caused by prolonged use of devices with digital screens. This paper reviews the principal environmental, ocular, and musculoskeletal causes for this condition. Due to the high prevalence of DES and frequent usage of digital devices, it is important that eye care practitioners be able to provide advice and management options based on quality research evidence.

Population perceived eye strain due to digital devices usage during COVID-19 pandemic.

PURPOSE: To assess the magnitude severity and determinants of eyestrain and the use of digital devices in a Saudi population during the COVID-19 pandemic lockdown. METHODS: This web-based survey was conducted in September 2020 and enrolled only Saudi nationals 15 years or older. Data were collected on demographics, eye strain related symptoms, severity, and the use of optical aids during the COVID-19 lockdown. The frequency and severity of eye strain were calculated. A Computer Vision Syndrome (CVS) score was graded as none/mild moderate and severe, based on the sum of 15-eye strain related signs and symptoms. Correlation analysis was performed for determinants of CVS. RESULTS: The study sample was comprised of 2009 individuals with median age of 20 years. Among those who used digital devices for more than 6 h daily, the main reasons for use were work and social purposes among 68.4%, and 61% of respondents, respectively. The prevalence of knowledge on CVS and the '20-20 rule for using digital devices' was 9.4% and 6.9, respectively. The most common symptoms of eye strain from digital device usage were headache, burning, itching, tearing, and redness of eyes. Six hours of daily usage of digital devices was positively associated to the grade of eye strain severity during the COVID-19 lockdown (P < 0.05)). CONCLUSION: The Saudi population experienced eye strain during COVID-19 lockdown due to excessive digital devices usage. Longer duration of digital device usage was associated to eye strain. Health care providers should educate the general population on measures to mitigate eye strain due to digital devices. Trial registration ID None applicable.

Prevalence and determinants of asthenopia among ophthalmologists in China: a national cross-sectional survey.

Introduction: The role of ophthalmologists is defined by tasks requiring visual effort, emphasizing the importance of examining their condition within the realm of occupational visual health. Our goal was to explore the occurrence of asthenopia among Chinese ophthalmologists and identify contributing factors through the use of a reliable and validated survey instrument. Methods: A national cross-sectional online survey was carried out in June 2017, involving 6,220 practicing ophthalmologists in China. Utilizing an 11-item Asthenopia Survey Questionnaire with established reliability and validity. Prevalence rates of asthenopia among subgroups categorized by age, gender, hospital classification, physician level, daily near vision activity duration, sleep duration, sleep quality, presbyopia status, and history of eye surgery were determined using the independent t-test, chi-square test and bonferroni test. Multiple logistic regression analysis was employed to pinpoint independent factors linked to asthenopia. Results: Out of the 5,009 ophthalmologists who completed the survey, a 40.7% prevalence of asthenopia was identified. Multivariate analysis revealed that good sleep quality (OR: 0.24, 95%CI: 0.20-0.30), moderate sleep quality (OR: 0.47, 95%CI: 0.38-0.59), engaging in daily near vision activities for less than 7 h (OR: 0.76, 95%CI: 0.68-0.86), having daily sleep duration exceeding 7 h (OR: 0.87, 95%CI: 0.77-0.98), and working in tertiary hospitals (OR: 0.88, 95%CI: 0.78-0.99) were protective factors against asthenopia. Conversely, presbyopia was identified as a risk factor (OR: 1.33, 95%CI: 1.04-1.70). All calculated p values were below 0.05. Age, gender, physician level, and eye surgery history were not related factors. Conclusion: Asthenopia is prevalent among Chinese ophthalmologists, with employment in tertiary hospitals providing a protective effect and presbyopia is a risk factor. Preventive strategies include improving sleep quality, restricting daily near vision activity to under 7 h, and extending daily sleep duration to over 7 h. Further investigation is needed to explore the protective implications of working in tertiary hospitals.

Prevalence and Association of Digital Eye Strain with the Quality of Sleep and Feeling of Loneliness among Female College Students in Northern India.

INTRODUCTION: Because of COVID's impact on social behavior, students have become more reliant on computer-facilitated communication to continue their studies and interact with friends. While it is known that the association between screen exposure and psychological well-being is both harmful and stronger among adolescents than younger children, what is less studied are the causal factors that may mediate the relationship. OBJECTIVES: The objectives of this study were to analyze the relationship between screen exposure and two psychological outcomes, sleep quality and loneliness, using digital eye strain as a mediating factor. Eye strain is expected to have a direct and harmful influence on psychological well-being. MATERIALS AND METHODS: A structured and validated questionnaire was transcribed and administered online. A nonrepresentative sample of 497 female college students in a North Indian city participated in the study. Digital eye strain, quality of sleep, and feeling of loneliness scores were assessed using latent class analysis. RESULTS: The selected latent model suggested that Class 2 had a high percentage of students with network issues, the problem with space and noise, and various financial hardships, which had almost doubled the rate of loneliness (53.28%) and sleep-wake difficulties (75.41%) among the students affected with computer vision syndrome (89.75%). CONCLUSION: There is an urgent need to examine the implications of digital exposure across gender and age to prevent future complications. Further, awareness for improving holistic well-being in the digital era should be promoted through various platforms.

Self-Reported Computer Vision Syndrome among Thai University Students in Virtual Classrooms during the COVID-19 Pandemic: Prevalence and Associated Factors.

During the COVID-19 pandemic, computer vision syndrome (CVS) related to online classrooms were unavoidable. This cross-sectional study aimed to explore the prevalence, characteristics and associated factors of CVS. A total of 527 students who were currently studying in a virtual classroom (70.40% female, mean (standard deviation; SD) age of 20.04 (2.17) years) were included. The prevalence of CVS assessed by an online CVS-Questionnaire was 81.0% (427/527). Comparing with those in the period before the online study, an increase in screen time (interquartile range) in students with and without CVS was 3 (0−3) and 2 (1−5) h, respectively. Overall, 516 students (97.9%) experienced at least one symptom. The most frequent symptom in CVS subjects was eye pain (96.5%). The most intense symptoms were the feeling of worsening eyesight (15.9%). The factors associated with CVS were female (p < 0.001), age (p = 0.010), atopic diseases (p = 0.020), prior ocular symptoms (p < 0.001), astigmatism (p = 0.033), distance from display <20 cm (p = 0.023), presence of glare or reflection on screen (p < 0.001), low screen brightness (p = 0.045), sleep duration (p = 0.030), inadequate break time between classes (p < 0.001) and increased screen time usage during online study (p < 0.001). Recommendations to prevent CVS based on the adjustable factors might reduce the burden of online study.

Digital eye strain and its associated factors in children during the COVID-19 pandemic.

Purpose: This study was undertaken to identify the prevalence of symptoms related to the use of display devices and contributing factors in children engaged in distance learning during the COVID-19 pandemic. Methods: An online electronic survey form was prepared using Google Forms (Alphabet Co., Mountain View, CA) and sent to parents of children under the age of 18 years engaged in distance learning during the COVID-19 pandemic. The types of display devices children use, how often such devices are used, the symptoms of digital eye strain, and the severity and frequency of the symptoms were recorded, and the associations between the factors were analyzed. Results: A total of 692 participants were included. The mean age of the children was 9.72±3.02 years. The most common display devices used were personal computers (n=435, 61.7%) for online classes and smartphones (n=400, 57.8%) for nonacademic purposes. The mean duration of display device use was 71.1±36.02 min without a break and 7.02±4.55 h per day. The most common reported symptom was headache (n=361, 52.2%). Of the participants, 48.2% (n=332) reported experiencing 3 or more symptoms. The multivariate analysis detected that being male (P=0.005) and older age (P=0.001) were independent risk factors for experiencing 3 or more symptoms. Conclusion: The increasing use of digital devices by children is exacerbating the problem of digital eye strain in children as a side effect of online learning. Public awareness should be improved.

Computer vision syndrome, visual ergonomics and amelioration among staff members in a Saudi medical college.

Objectives. Nearly 60 million people suffer from computer vision syndrome (CVS) globally, resulting in reduced work productivity. This study aimed to determine the prevalence of CVS, describe the working conditions, visualize ergonomic factors and determine preventive measures application among university staff members. Methods. A cross-sectional study was conducted with university medical staff members using a semi-structured questionnaire that included a validated CVS questionnaire. Results. CVS prevalence was 81.2%. Dryness, headache, feeling that sight is worsening and difficulty in focusing on near vision were the most experienced symptoms. Prevalence of CVS was significantly higher among females (52.3%), those having a higher mean work duration (21.65 ± 7.55 years), those who frequently use a smartphone (84.9%) and those spending most of their screen time during both day and night (87.1%). Visual ergonomics and preventive measures application, such as correct screen level, regular cleaning of the screen, appropriate illumination and use of eye drops, were significantly associated with negative CVS. Conclusions. These results raised attention to the essential need for visual assessment of university staff members for early and proper diagnosis of CVS to minimize its impact on working performance. Accordingly, it is recommended to organize university-based awareness programs regarding CVS for working personnel.

Computer vision syndrome and its associated ergonomic factors among bank workers.

Objectives. This study aimed to describe the prevalence of ergonomic factors associated with computer vision syndrome (CVS), and knowledge and practices of computer usage among bank workers in the Cape Coast Metropolis, Ghana. Methods. A comprehensive eye examination was performed for 139 bankers in the Cape Coast Metropolis. Measurements of ergonomic practices at workstations were carried out and self-administered questionnaires were used to collect socio-demographic data, symptoms of CVS and associated factors as well as knowledge, attitudes and practices of the bankers on CVS. Descriptive statistics and logistic regression were carried out to compute the different proportions and relevant associations. Results. Headaches (73.4%), eyestrain (65.5%) and itching (63.3%) were the most common reported symptoms. The prevalence of CVS in the study population was 71.2% with a high level of poor ergonomic practices (78.4%) at computer workstations. With regard to knowledge, attitudes and practices of the participants on CVS, 68.3% of the participants had low levels of knowledge on CVS, while 90.6% had negative attitudes towards CVS and 46.0% of the participants had poor practices. Conclusion. Bankers had a high prevalence of CVS. Ergonomic practices, females and computer usage were all associated significantly with the presence of CVS.

Refractive and Binocular Vision Status and Associated Asthenopia among Clinical Microscopists.

Background Clinical microscopists are at a greater risk of developing binocular vision anomalies and asthenopia. Objective To assess the refractive and binocular vision status and to explore the association between the presence of asthenopic symptoms and microscopy work among clinical microscopists working at medical laboratory department. Method This cross-sectional study involved 37 clinical microscopists working at medical laboratory department of Dhulikhel Hospital, Nepal. The study was conducted from January to December 2013. Only those participants who had been using microscope for at least a year were enrolled in this study. Each participant underwent distance visual acuity (VA) assessment, refractions, and orthoptic evaluation, including measurement of distance and near phoria, near point of convergence (NPC), near point of accommodation (NPA), positive fusional vergence (PFV), adduction, and calculation of accommodation convergence/accommodation (AC/A) ratio. The tear test was also carried out in each subject. Information about use of glasses, microscopy work (duration, and time spent per day in microscope), and visual symptoms associated with the use of microscope such as eye strain, headache, double vision, and near vision were collected. Result The mean age of the clinical microscopists was 29 ± 5.7 years. The prevalence of refractive error was 56.76% and the mean spherical equivalent (SE) refractive error was -0.77 ± 0.86 D. Refractive error had neither correlation with microscopy work and asthenopic symptoms associated with it, and nor with binocular vision parametersNPC, AA and AC/A ratio. However, there was a positive association between asthenopic symptoms and microscopy work. There was statistically significant difference between symptomatic and asymptomatic subjects for binocular vision parameters, including NPC, AA and positive fusional vergence (PFV) for near. Conclusion Microscopy work has an impact on near binocular vision. Asthenopic symptoms bear a positive association with microscopy work. Refractive error has no significant correlation with either microscopy works or associated asthenopic symptoms.

Astenopia em docentes universitários durante a pandemia da COVID-19 / Asthenopia in college lecturers during the COVID-19 pandemic

RESUMO Objetivo: Avaliar sintomas astenópicos e fatores sociodemográficos, hábitos comportamentais e clínicos nos docentes universitários durante a pandemia da COVID-19. Métodos: Trata-se de estudo transversal que avaliou a ocorrência de astenopia em 104 docentes. Questionários de sintomatologia visual validados foram adaptados para a coleta de dados. Houve comparação dos docentes quanto à ocorrência ou não de sintomas astenópicos, bem como foi aplicada regressão logística binária, para aferir a associação com variáveis independentes (p<0,05). Resultados: Houve maior aparecimento de sintomas astenópicos durante o período pandêmico, em que o tempo de exposição a telas parece ter sido o fator mais determinante. Além disso, os indivíduos com tempo de tela superior a 5 horas diárias, que faziam uso de telas para o lazer e usavam colírio/lubrificantes apresentaram significativamente maior chance de estar no grupo com sintomas astenópicos. Conclusão: Foi identificada associação significativa entre a ocorrência de sintomas astenópicos e o uso de telas durante o período pandêmico, principalmente nos grupos com maior duração do tempo de tela. O estudo chama atenção para a saúde ocular de docentes universitários em ensino remoto, além de suscitar novos estudos para investigação desse quadro em distintos ambientes escolares.

ABSTRACT Objective: To assess asthenopic symptoms and sociodemographic factors, behavioral and clinical aspects in college lecturers during the COVID-19 pandemic. Methods: This is a cross-sectional study evaluating asthenopia in 104 lecturers. Some validated visual symptom questionnaires were adapted for data collection. Lecturers were compared regarding the occurrence or not of asthenopic symptoms, and binary logistic regression was applied to measure the association with independent variables (p<0.05). Results: Asthenopic symptoms occurred more often during the pandemic, when exposure to screens was a determinant factor. The individuals with screen time longer than five hours a day, who used screens for leisure, and who used eye drops/lubricants were significantly more likely to be in the group with asthenopic symptoms. Conclusion: A significant association was identified in occurrence of asthenopic symptoms and screen use during the pandemic period, especially in groups with longer screen time. The study draws attention to the eye health of college lecturers in distance learning, and the need for further research on this situation in different school environments.

Contribution of Total Screen/Online-Course Time to Asthenopia in Children During COVID-19 Pandemic via Influencing Psychological Stress.

Objectives: During the coronavirus disease 2019 (COVID-19) self-quarantine period, the transition to online-course has profoundly changed the learning modes of millions of school-aged children and put them at an increased risk of asthenopia. Therefore, we aimed to determine associations of the total screen/online-course time with asthenopia prevalence among that children during the COVID-19 pandemic, and whether the associations were mediated by psychological stress. Methods: Asthenopia was defined according to a validated computer vision syndrome questionnaire (CVS-Q). We used CVS-Q to collect the frequency and intensity of 16 asthenopia-related eye symptoms of 25,781 children. Demographic features, eye care habits, visual disorders, lifestyle, psychological and environmental factors, were also collected. Results: The overall asthenopia prevalence was 12.1%, varying from 5.4 to 18.2% across grade/gender-classified subgroups. A 100-h increment of total screen/online-course time were associated with an increased risk of asthenopia by 9% [odds ratio (OR) = 1.09] and 11% (OR = 1.11), respectively. Mediation analysis showed that the proportions of total effects mediated by psychological stress were 23.5 and 38.1%, respectively. Age, female gender, having myopia or astigmatism, bad habits when watching screens were also risk factors. Conversely, keeping 34-65 cm between eyes and screen, increased rest time between classes, and increased eye exercise were all associated with a decreased risk. Conclusion: Our study indicated that the influence of long total screen or online-course time on psychological stress increases asthenopia risk. The findings of this study have provided a new avenue for intervening screen-related asthenopia in addition to incorporating a reasonable schedule of online courses into educational policy.

[Digital eye strain. Symptoms, prevalence, pathophysiology, and management]. / Perturbations oculaires secondaires à l'utilisation de supports numériques. Symptômes, prévalence, physiopathologie et prise en charge.

The digital revolution, which has been underway since the 1980's, is disrupting our daily routines with an exponential increase in the use of screens, which has not been without consequence to our visual system. Digital eye strain (DES), or computer vision syndrome (CVS), includes all the visual symptoms secondary to the use of digital devices. DES is present in at least 50% of regular users of digital media and is defined by blurred vision, difficulty focusing, ocular irritation or burning, dry eye, visual fatigue, headaches and increased sensitivity to light. Exposure time, age, female gender, and work environment are the main factors increasing its prevalence. Its pathophysiology, still poorly understood, is felt to be multifactorial and includes disturbances in the accommodative-convergence balance and changes in the ocular surface. Regarding accommodation and convergence, the studies are mostly old and their results heterogeneous. Conversely, many studies have shown an increase in the prevalence of dry eye in screen users. Although the retinal toxicity of blue light has been proven in in vitro models, the low level of evidence in the available studies does not allow it to be clearly correlated with the symptoms of DES. The objective of this review is to condense the knowledge available in the literature on the symptoms, prevalence, pathophysiology and management of DES.