Prevalence of Computer Vision Syndrome and Patterns of Electronic Devices Usage before and during COVID-19 Pandemic among Medical Students in Riyadh, Saudi Arabia

Purpose: To estimate the prevalence of CVS (computer vision syndrome) among university medical students in Riyadh, Saudi Arabia after establishing remote learning during COVID-19 pandemic and to compare patterns and settings of electronic devices used by students before and during this pandemic. Methods: This is an observational descriptive cross-sectional study. 1 st to 5 th year medical students actively enrolled at the governmental colleges of medicine in Riyadh were asked to ll an electronic online questionnaire. The questionnaire included demographic information and various variables to be studied. Results: A total of 300 medical students were included in this study. 282 (94.0%) reported at least one symptom of CVS. The most frequently reported symptoms were musculoskeletal: neck, shoulder and back pain in 253 (84.3%), headache in 213 (71.1%) and dry eyes in 204 (68%). 38% of the students experienced more severe symptoms while 48% experienced more frequent symptoms during COVID-19 pandemic. The risk factors for experiencing three or more symptoms of CVS were using electronic devices for longer periods (6.8 hours ±2.8) during COVID-19 (p<0.001) OR 1.21 [1.09-1.35] 95% CI, and being of female gender (p<0.001) OR 3.29 [2.00-5.43] 95% CI. Conclusion: CVS prevalence during COVID-19 era among medical students is high. This necessitates increasing the awareness of CVS and its preventive measures.


Introduction
Nowadays, looking at electronic screens has become an inseparable part of our lives. This was more exaggerated ever since the beginning of the COVID-19 Pandemic, as governments closed educational campuses worldwide during lockdowns. In March 2020, the Ministry of Education in Saudi Arabia directed all universities to shift teaching to remote learning [1].
Extended hours of studying and spending leisure time on electronic screens may lead to increased prevalence of Computer Vision Syndrome (CVS) which is known as digital eye strain. It is de ned by the American Optometric Association as "a group of eye-and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use" [2]. The most common manifestations of CVS are eye strain, headache, blurred vision, dry eyes as well as neck and shoulder pain. Additionally, poor lighting, glaring at digital screens, improper viewing distances and poor sitting posture may exacerbate and worsen these symptoms.
A study published from Al-Majmaah University, Saudi Arabia prior to the pandemic concluded that the prevalence of visual symptoms related to computer use was 54.8% among university students [3].
Another study conducted in Nepal has estimated the prevalence of CVS in medical students to be 71.6% [4]. Furthermore, one study in Chennai, India, found that 78.6% of medical students had CVS [5]. During the COVID-19 pandemic, few studies assessed the prevalence of CVS among students. Two studies conducted in India and one in Pakistan showed a high prevalence of CVS with 88%, 93.6% and 98.7% of their participants respectively had at least one eye symptom [6][7][8].
In our study, we aim to estimate the prevalence of CVS among university medical students in Riyadh, Saudi Arabia after establishing remote learning during COVID-19 pandemic and to compare patterns and settings of electronic devices used by the students before and during COVID-19 pandemic.

Inclusion and exclusion criteria
This is an observational descriptive questionnaire-based cross-sectional study. The participants are 1st to 5th year medical students who are actively enrolled at the governmental colleges of medicine in Riyadh, : King Saud University (KSU), King Saud Bin Abdulaziz University for Health Sciences (KSAUHS), Imam Mohammad Ibn Saud Islamic University (IMSIU) and Princess Nourah Bint Abdulrahman University (PNU).
The exclusion criteria included students with known ocular pathology like glaucoma, strabismus, severe trauma, undergone refractive surgery for vision correction within the last 6 months or other ocular or eyelid surgeries that may affect the ocular surface health. Also, students with underlying systemic illness like Hypertension, Diabetes, Autoimmune disorders or using medications that have known visual side effects like (isotretinoin, bisphosphonates, Cyclosporine, Tetracyclines, Hydroxychloroquine, Antituberculosis and Anticholinergics) and those who apply topical eye drops other than Arti cial tears (Corticosteroids, Antibiotics, Antivirals, glaucoma medications, Anesthetics or Mydriatics) were excluded from the study.

Sample size estimation:
The sample size of the study was estimated based on the assumption that the prevalence of computer vision syndrome is around 58% among medical students, with a precision of ±5%, and 95% con dence interval. The minimal sample size required was calculated to be 375 participants.

Data collection tool:
The data of the study were collected through a questionnaire based on already published studies with three validated questionnaires used in references [9,10,11]. The questionnaire consisted of four parts: the rst part collected demographic information, the second part explored Knowledge, attitude and practice of the students regarding CVS, the third part discussed frequency and severity of eye symptoms and the fourth and last part enquired about the usedpatterns and settings of electronic devices in daily use before and during the COVID-19 pandemic. The developed questionnaire was reviewed by two senior faculty members, one consultant from the ophthalmology department and another faculty from the department of public health. A pilot study was conducted on 15 students to assess their understanding and the time needed to complete the questionnaire.

Data collection:
Data collection was carried out in the period from April to May 2021 through an electronic selfadministered questionnaire distributed to medical students by social media platforms.
An online consent form appeared in the rst page of the electronic questionnaire and it was obtained from all potential participants. The participants have a clear explanation of the bene ts of their participation and any potential risks. The Participation in the study was completely voluntary and the participants have the right not to complete the study at any time. Con dentiality and privacy of each participant have been assured. The participants' details have been completely anonymous, and they have been used for data analysis only.

Statistical Analysis:
Data were collected, managed and coded in a spreadsheet using Microsoft Excel 2010® software and they were analyzed using SPSS® version 21.0 (IBM Inc. , Chicago, Illinois, USA).
Descriptive analysis was done, where categorical variables were presented in the form of frequencies and percentages. Data exploration using Shapiro-Wilk test was done for the continuous variables where the data was found to be normally distributed. Mean ±SD [Range] was reported, otherwise median (interquartile range) (IQR) was reported. Independent t-test and paired samples t-test were used for comparisons between two groups for the continuous variables and Chi-squared test for comparing proportions among the studied groups. Any output with a p below 0.05 was interpreted as an indicator of statistical signi cance.

Results
A total of 300 out of 375 medical students were included in this study. 75 responses were excluded after applying the exclusion criteria. The majority of respondents were females (176, 58.6%) (Table1).When assessing the awareness of CVS, 76.3% of our participants never heard of the syndrome. 282 (94.0%) of the respondents reported at least 1 symptom. The most frequently reported symptoms in our study were musculoskeletal in neck, shoulder and back pain (253, 84.3%), headache (213, 71.1%) and dry eyes (204, 68%). (Figure 1) The breakdown of severity of each symptom is shown in Table 2a.       (Table 2b).
Our study explored the frequency and severity of CVS symptoms among study participants.
At least one symptom of CVS was reported by 282 participants (94.0%). 47% of students experienced CVS symptoms on sporadic episodes or once a week (occasionally). 31.3% experienced the symptoms 2-3 times a week (often). 13% never had any CVS symptoms over the last 3 months. Only 8.7% reported CVS symptoms on a daily basis (always). During the COVID-19 pandemic, symptoms were reported severer and more frequent by 38% and 48.3% of students respectively. Among those who used arti cial tears n=241, 42% experienced improvement in the CVS symptoms with the use of arti cial tears. (Table  2c).
The longer the duration of use was, the severer and more frequent the symptoms were with p value of <0.001. (Table 2d) The association between taking breaks from one hand and severity and frequency of symptoms was not statistically signi cant. (Table 2e).
One quarter (26%) of the respondents reported spending 8 hours or more on electronic devices pre COVID-19. During the pandemic, the percentage increased up to 56.7% (p <0.001). Also, the average of the total studying hours on devices was 5.1 hours pre COVID-19 and it increased to 6.4 hours during the pandemic (p<0.001). Smartphones were used by 34% of students prior to COVID-19. This percentage decreased to 23% during the pandemic (p=0.002). While using electronic devices, only 22.7% do not take breaks.
Among the other 77.3% who took breaks, negligible differences in the frequency and duration of breaks existed. There was no statistical signi cance between the preferred monitor brightness and room illumination pre and during COVID-19 pandemic (Table 3a).  Minute differences were found among the patterns and settings of electronic devices used before and during COVID-19 pandemic with no statistical signi cance. 8% of the respondents utilized the 20-20-20 rule before COVID-19 and the remained percentage unchanged during the pandemic (9.7%). Similarly, locating the screen at 20-28 inches distance was only applied by 16.3% before the pandemic and 18.7% after the pandemic. 27.3% of the respondents reported wearing their corrective lens (contact lenses/glasses) while using electronic devices prior to the pandemic. The remained percentage was almost the same during the pandemic (29.3%). (Table 3b).

Discussion
The Ministry of Education of Saudi Arabia directed the universities and schools to shift to remote learning, so students can attend all their classes from home via electronic platforms like blackboard, ZOOM and Microsoft Teams to ensure their safety and health. But the continuation of E-learning during the COVID-19 era has several drawbacks.
High prevalence of CVS was observed. In our study, 282 students reported at least one symptom (94.0%) which is consistent with the prevalence reported during covid-19 pandemic in Pakistan (98.7%) and India (88%) [6,7] and also similar to the prevalence in Jeddah, Saudi Arabia before the pandemic (97.3%) [12].
However, in the previous studies, there was no exclusion to students with ocular or systemic illness or to those applying medications with known visual side effects. In our study, all those confounders were eliminated.
In the current study, the most reported symptoms were neck, shoulder and back pain, headache and dry eyes which is similar to what was reported in a previous study among business and medical college students in Riyadh, Saudi Arabia [13], but with a higher percentage in our study; it could be attributed to the increasing duration of e-learning.
In our study, being female increased the risk of having three or more symptoms with a statistical signi cance. It is matching with what was reported in multiple studies before [3,10,12]. This could be attributed to the higher prevalence of dry eyes and cosmetics use among females [9] and to the gender difference in response to pain [14].
The relation between refractive errors and developing CVS has con icting results in the literature. In our study, we found that having refractive errors as myopia, hyperopia or astigmatism were not risk factors for having more symptoms of CVS. This is almost similar to a national study conducted in Jeddah which found that myopia and hyperopia were not associated with CVS, but astigmatism showed signi cant association with more symptoms [10]. In contrast, in another national study in Al-Qassim region there was a signi cant relation between myopia and CVS, especially those corrected with contact lenses [15]. On the international level, a systematic review concluded that those who have refractive errors are at a higher risk to develop CVS or suffer from more severe symptoms of CVS [16]. Moreover, a study conducted in Nepal found that students who have myopia corrected with glasses are at higher risk to develop CVS. However, the study did not nd a statistically signi cant difference between students who hadhigh myopia and those who had low and moderate myopia in regard to developing CVS [17].
In assessing the awareness of CVS, 76.3% of our participants never heard of the syndrome.
Similar percentage was reported by a study conducted in Nepal where 77.1% of their study population had no pre-existing knowledge of CVS [4]. This highlights the need for more awareness programmes of CVS and its risk factors.
Along with the increased dependence on online education during the pandemic, safe habits in digital device use have been recommended especially in regard to the duration of device use as we found it to be one of the most statistically signi cant factors in our study. We found out that students who used electronic devices for longer durations during COVID-19 (6.8+_2.8) reported 3 or more symptoms of CVS with p-value (<0.001). The ration of our respondents who reported spending 8 hours or more using electronic devices increased signi cantly from only 26% pre COVID-19 to 56.7% during the pandemic (p <0.001). Also, the average total studying hours increased from a mean of 5.1 hours reported prepandemic to a mean of 6.4 hours during this era with p-value (<0.001) The increase in symptoms due to longer device use is matching with multiple previous studies that have reported participants experiencing more symptoms after using devices for more than six hours a day [18,19].On the opposite side, some studies reported that there is no association between the duration of usage of the device and the number of symptoms [12].
The pattern and settings of electronic devices used by our participants remained unchanged pre and during Covid-19. In addition, the majority of the study population were not following preventive measures such as reducing hours of use, room illumination, and monitoring the brightness. In addition, using the 20-20-20 rule and locating the screen at 20-28 inch from your eyes were only applied by a minor percentage of the study population with no signi cant difference pre and during Covid-19.
These results could be explained by the poor level of awareness among the study participants. Even Tthough 55.3% of the respondents knew about the 20-20-20 rule, only 8% actually applied the rule pre Covid-19 and 9.7% during Covid-19.

Conclusion
High prevalence of CVS symptoms during COVID-19 era was reported, Having three or more symptoms was statistically signi cant among females. The duration of use during Covid-19 pandemic was associated with more frequent and more severe CVS symptoms. The most Commonly reported symptoms were neck, shoulder and back pain, headache and dry eyes.

Recommendations and limitations
Our study highlights high prevalence of CVS among medical students which was expected due to the COVID pandemic lockdown and shift to online teaching. However, we encourage future researchers to perform larger community-based studies as there is an expected increase in digitalization for educational and recreational purposes as well.
Unexpectedly, our study shows a low level of awareness among medical students regarding knowledge of CVS and practical ergonomics. This highlights the need to increase the awareness of CVS through introducing the subject in university's curriculum and frequent campaigns.
Our study was cross sectional and based on a questionnaire which assessed the prior 3 months.
Larger studies are required to verify our results. Due to limited accessibility to university students and lack of a national database, our study targeted only medical students in government universities in Riyadh which does not re ect the whole population.

Declarations
Competing Interests: None Funding: No funding was received for conducting this study Financial interests: the authors have no relevant nancial or non-nancial interests to disclose.

Figure 1
The most frequently reported symptoms