Literature DB >> 35673319

The Effect of Online Education on Healthy Eyes of Saudi Teachers in the COVID-19 Pandemic: A Local Study.

Saif K Dossari1, Rahaf AlZahrani2, Halal Alutaibi3, Bayan Al Shuhayb2, Tamim Alsultan2, Hanan A Albenayyan2, Bashayer F Al Furaikh3.   

Abstract

Background Digital eye strain (DES) or computer vision syndrome (CVS) manifests as eye fatigue caused by prolonged exposure to screens and exaggerated by some attitudes. Online education plays a crucial role in helping schools, instructors, and universities ensure the continuity of the education process during the COVID-19 pandemic. There is a lack of attention given to the effects of online teaching on teachers' eyes health during the pandemic and is nearly nonexistent. Hence, we aim to evaluate this among teachers in the Eastern Province of Saudi Arabia. Methodology A cross-sectional electronic self-administered questionnaire was distributed through social media applications among teachers in the eastern province of Saudi Arabia. The survey contained three main parts: biographical data, educational status, and eye health scale before and during the pandemic. All statistical analysis was done using IBM SPSS version 22 (IBM Corp., Armonk, NY). Results A total sample of 301 teachers was identified with ages ranging from 22 to 60 years, the majority were female (75.4%). Twenty-four point nine percent (24.9%) of the sample have a chronic disease, and 17.3% had previous LASIK surgery. Twenty-four point nine percent (24.9%) spent two to five hours teaching before the pandemic versus 60.8% with online education during the pandemic spent two to five hours daily. Fifty-two point eight percent (52.8%) of the teachers kept the distance between them and the digital screen at less than 50 cm. Eighty-one point four percent (81.4%) of teachers reported severe to moderate effects of online teaching using a computer/tablet/phone on their eye health. Fifty-two point two percent (52.2%) reported headache. Conclusion There is an obvious negative effect reflected by subjects' symptomatology and complaints in their eyes. This should prompt health authorities to provide better teaching equipment and accessibility to essential eye care to teachers.
Copyright © 2022, Dossari et al.

Entities:  

Keywords:  covid- 19; digital eye strain; digital screens; dry eye; ophthalmology

Year:  2022        PMID: 35673319      PMCID: PMC9165422          DOI: 10.7759/cureus.24721

Source DB:  PubMed          Journal:  Cureus        ISSN: 2168-8184


Introduction

Since December 2019, the world has experienced a rapid spread of the new coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2), a variant of coronavirus [1]. The World Health Organization (WHO) declared a pandemic on March 11, 2020. Hand contact or inhalation of viral droplets are the main transmission routes of coronavirus, which resulted in the rapid spread of the disease. Therefore, hygiene and social distancing are the main preventive methods to control the pandemic [2]. Many governments worldwide have taken severe measures to prevent the transmission of the virus. In particular, since February 2020, 191 countries have initiated the initial steps to suspend the educational institutions, including schools and universities, as part of these measures, and classroom teaching was replaced by online education-training activities [3]. Online education plays a crucial role in helping schools, instructors, and universities ensure the continuity of the education process during the COVID-19 pandemic. However, even though online education reduces transmission rates, it may harm eye health. Both students and the teaching faculty were left in front of screens for long periods during this process. These devices inflict damage by releasing short, high-energy waves that can penetrate the eyes and ultimately damage the retinal cells photochemically. Therefore, it makes a person more susceptible to eye problems, ranging from dry eyes to age-related macular degeneration. Collectively, it is referred to as digital eye strain (DES) or computer vision syndrome [4-5]. The American Optometric Association defines digital eye strain (DES) or computer vision syndrome as a wide range of visual and ocular symptoms caused by eye fatigue from prolonged exposure to screens [6]. Eye fatigue or computer vision syndrome (CVS) encompasses various symptoms such as eye discomfort, blurred vision, headache, lacrimation, dryness, redness, inability to focus, and neck and shoulder pain [7]. If a person spends more than two hours per day in front of a computer screen, he is more prone to develop those CVS symptoms [8-9]. CVS is a severe condition that affects attention and daily performance. In addition, CVS is caused by a reduced blinking reflex when focusing on a screen, resulting in exaggerated dry eyes, which is considered a significant contributor to the symptoms [10-12]. Other factors, such as usage duration, number of breaks, screen brightness, distance from the screen, and sitting posture, have been addressed in previous studies and established as risk factors for CVS [10,13]. Before COVID-19, many studies have found that CVS is common among office workers in general. For example, in 2016, one study discovered a prevalence of 67.4% among computer office employees, with females being more susceptible to the disease [14]. In addition, at the time of the pandemic, several publications showed increased rates of CVS-associated symptoms among the general population, children, and students in particular with similar associated risk factors such as increased computer usage rate per day, decreased screen distance, and pre-existing eye disease [15-19]. With the conversion of all the teaching classrooms to online classes, it is expected to have increased rates of eye fatigue or CVS among both students and teachers. However, to the best of our knowledge, the literature concerning the effect of online teaching on teachers’ eye health during the pandemic is not having enough attention and is nearly nonexistent. Therefore, the study aims to measure the effect of online education on the eye health of teachers and identify the possible risk factors of eye fatigue among them. The findings of this study will aid in recognizing the issue, raising awareness about it in their daily practices, and implementing prevention steps to reduce CVS-related symptoms.

Materials and methods

Study design and participants A cross-sectional study was carried out in the eastern province of Saudi Arabia, from October 17, 2021, to February 20, 2022, to evaluate the effect of online education on eye health among Saudi teachers in the eastern province of Saudi Arabia. The minimum sample size was determined by the Richard Geiger equation to be 385 with a 95% confidence interval and a 5% margin of error. Both genders of Saudi teachers who participated in online teaching during the pandemic in the Eastern Province were included. Any participant who was not a teacher from the Eastern Province or did not complete all questions was excluded. Data collection method An electronic self-administered questionnaire was distributed through social media applications such as WhatsApp. The questionnaire used in this study is self-structured with the revision of multiple ophthalmologists and general physicians to cover research objectives. The questionnaire is composed of three parts: 1. The first part contained demographical data, including age and gender. 2. The second part contained the educational status concerned with collecting data related to the academic status, specialty, teaching methods during the pandemic, the platform used during the pandemic, and the online daily hours spent before and during the pandemic. 3. The third part was contained the eye health scale in the pandemic concerned with collecting data related to eye health regarding the use of online teaching, associated symptoms and their frequency and intensity, and situational assessment, including blinking changes, distance from the screen, screen brightness, and eye gaze position. Statistical Analysis After data extraction, they were revised, coded, and fed to statistical software IBM SPSS version 22 (IBM Corp., Armonk, NY). All statistical analysis was done using two-tailed tests, and a P-value less than 0.05 was statistically significant. Descriptive analysis was done based on the frequency and percent distribution for all variables, including teachers' personal data, ophthalmic history, online teaching, and related positions with the effect of online teaching on teachers' eye health and related symptoms. Cross-tabulation was used to assess the distribution of the eye health effects of online teaching during the COVID-19 pandemic among study teachers, their personal data, medical data, and online teaching data. The significance of relations was assessed using the Pearson chi-square test and exact probability test for small frequency distributions. Ethical Considerations After fulfilling all the needed ethical issues, ethical approval was obtained by the Institutional Research Board (IRB) and the Research Ethics Committee of King Faisal University in Al-Ahsa. The questionnaire contained a brief explanation of the aims of the study. Informed consent of all participants was taken before data collection.

Results

A total sample of 301 teachers fulfilling the inclusion criteria completed the study questionnaire. Teachers’ ages ranged from 22 to 60 years, with a mean age of 38.6 ± 12.7 years. About 227 (75.4%) teachers were females. As for chronic health problems, 26 (8.6%) had diabetes mellitus (DM), 18 (6%) were hypertensive, and 31 (10.3%) had other sporadic health problems. A total of 221 (73.4%) had no chronic health problems. Also, 52 (17.3%) of the schoolteachers had previously undergone LASIK surgery while 240 (79.7%) had no history of eye surgery (Table 1).
Table 1

Bio-demographic data of sampled teachers for online learning, Eastern region, Saudi Arabia

DM: diabetes mellitus; HTN: hypertension

Bio-demographic dataNo%
Age in years  
22-353812.6%
36-5022976.1%
51-603411.3%
Gender  
Male7424.6%
Female22775.4%
Had chronic health problems?  
DM268.6%
HTN186.0%
Asthma51.7%
Others3110.3%
None22173.4%
Have you ever had eye surgery?  
LASIK5217.3%
Others93.0%
No24079.7%

Bio-demographic data of sampled teachers for online learning, Eastern region, Saudi Arabia

DM: diabetes mellitus; HTN: hypertension Table 2 shows the ophthalmic history among teachers in the Eastern region, Saudi Arabia. One-hundred seventy-three (57.5%) of the school teachers had previously visited an ophthalmologist. The leading causes for this visit were the correction of refractive errors (74%), followed by eye dryness (6.9%), eye allergy with itching (6.4%), blurred vision (7.5%), and 9.2% for other reasons.
Table 2

Ophthalmic history among teachers in the Eastern region, Saudi Arabia

Ophthalmic historyNo%
Have you ever visited an ophthalmologist?  
Yes17357.5%
No12842.5%
Causes of visiting ophthalmologist  
Refractive error12874.0%
Dryness126.9%
Lacrimation with itching116.4%
Blurred vision137.5%
Others169.2%
Have you ever used moistening eye drops?  
Yes4852.2%
No4447.8%
Have you ever had eye surgery?  
LASIK5217.3%
Others93.0%
No24079.7%
Table 3 shows the online teaching provided by school teachers during the COVID-19 pandemic in the Eastern region, Saudi Arabia. As for teaching methods during the COVID pandemic, online learning with interactive participation was the most used method (82.1%), followed by online learning with uploading materials (54.2%), online learning without interactive participation (16.9%), and using virtual classrooms with Microsoft PowerPoint (2.3%; Microsoft Corporation, Redmond, WA). Regarding the used platforms, Microsoft Teams (Microsoft Corporation) was used by 83.4% of the teachers, followed by Zoom (25.2%; Zoom Video Communications, San Jose, California), the platform (12%), and Classera (5.3%; San Francisco, CA). About daily hours spent on online teaching before the COVID pandemic, 13% spent about one hour daily, 24.9% spent two to five hours, 15.6% spent more than five hours, while 46.5% never used online learning before the pandemic. About daily hours spent on online teaching after the covid pandemic, 60.8% spent two to five hours, 35.2% spent more than five hours, and only 4% spent one hour daily.
Table 3

Online teaching provided by the study teachers during the COVID-19 pandemic, Eastern region, Saudi Arabia

Online teachingNo%
Teaching methods during theCOVID pandemic  
Online learning with interactive participation24782.1%
Online learning with uploading materials16354.2%
Online learning without interactive participation5116.9%
Using virtual classrooms with PowerPoint72.3%
Displaying videos, games, and competitions1.3%
What was the used platform  
Microsoft Teams25183.4%
Zoom7625.2%
The platform3612.0%
Classera165.3%
Webex62.0%
Daily hours spent on online teaching before the COVID pandemic  
1 hour3913.0%
2-5 hours7524.9%
> 5 hours4715.6%
Not used14046.5%
Daily hours spent on online teaching after the COVID pandemic  
1 hour124.0%
2-5 hours18360.8%
> 5 hours10635.2%
Table 4 shows the teachers' positions and distance during online learning during the COVID-19 pandemic, in the Eastern region, Saudi Arabia. About 52.8% of the teachers keep distance between them and the digital screen display while using the device of less than 50 cm while 43.2% keep a distance of 50 cm. As for screen brightness while using the device, 75.4% use average brightness, only 6.3% use low brightness, and 18.3% use high/very high brightness. Considering the position of the eyes towards the screen, it was straight ahead among 68.8% users, down a little among 28.9%, and a little higher among 2.3%.
Table 4

Teachers' positions during online learning with the COVID-19 pandemic, Eastern region, Saudi Arabia

Online learning positionNo%
The distance between you and the digital screen display while using the device  
< 50 cm15952.8%
50 cm13043.2%
> 50 cm124.0%
Screen brightness while using the device  
Low196.3%
Normal22775.4%
High4214.0%
Very high134.3%
The position of the eyes toward the screen  
Down a little8728.9%
Straight ahead20768.8%
A little higher72.3%
Table 5 shows the teachers' eye health with online learning during the COVID-19 pandemic, in the Eastern region, Saudi Arabia. About 84 (27.9%) teachers reported the severe effect of online teaching using a computer/tablet/phone on their eye health, while 161 (53.5%) had a moderate effect and 56 (18.6%) had no effect. As for eye symptoms related to dryness, 43.5% complained of a feeling of stinging, burning, or roughness in the eyes, followed by eye redness (39.2%), excessive lacrimation (34.6%), blurred vision (34.6%), photosensitivity (32.9%), feeling of having a foreign body in the eyes (29.2%), difficulty driving at night (10.6%), sticky discharge in or around the eyes, and difficulty wearing contact lenses (4% each). Regarding myopia symptoms, the headache was the most reported (52.2%), followed by difficulty concentrating (34.9%), pain and fatigue in the eyes, especially when looking at distant objects and staring (31.9%), blurred vision (26.9%), and diplopia (10%). As for symptoms frequency, 127 (55.7%) had these symptoms rarely or once a week. Symptoms were mild among 31.6% of the teachers, moderate among 45.2%, and severe among 23.2%. Almost 29.9% of the teachers noticed increased changes in blinking during the pandemic while 57.5% had no change but decreased among 12.6%.
Table 5

Teachers' eye health with online learning during the COVID-19 pandemic, Eastern region, Saudi Arabia

Eye healthNo%
Effect of online teaching using computer/tablet/phone on your eye health  
Severe effect8427.9%
Moderate effect16153.5%
No effect5618.6%
Eye symptoms related to dryness  
None4815.9%
A feeling of stinging, burning, or roughness in the eyes13143.5%
Eye redness11839.2%
Excessive lacrimation10434.6%
Blurred vision10434.6%
Photosensitivity9932.9%
Feeling of having feedback in the eyes8829.2%
Difficulty driving at night3210.6%
Sticky pus in or around the eyes124.0%
Difficulty wearing contact lenses124.0%
Myopia symptoms  
None7324.3%
Headache15752.2%
Difficulty concentrating10534.9%
Pain and fatigue in the eyes, especially when looking at distant objects and staring.9631.9%
Blurred vision8126.9%
Diplopia3010.0%
Frequency of these symptoms  
Sometimes (rarely or once/week)12755.7%
Usually (daily to 3 times/week)10144.3%
Severity of these symptoms  
Mild7231.6%
Moderate10345.2%
Severe5323.2%
Have you noticed changes in your eyelashes "blink" during the pandemic  
Increased9029.9%
Decreased3812.6%
No change17357.5%
Table 6 shows the eye health effect of online learning on teachers’ demographic, teaching, and position. A moderate to severe effect on eye health was reported by 82.4% of teachers aged 51-60 years compared to 63.2% of those aged 22-35 years with recorded statistical significance (P=.001). Also, 87.7% of female teachers had moderate to severe effects compared to 75% of males (P=.001). Spending more than five hours on online learning before the COVID-19 pandemic was associated with moderate to severe effects on 87.2% of teachers’ eye health versus 89.7% of those who spent one hour (P=.005). During the pandemic, spending more than five hours was associated with moderate to severe effects on the eye health of 89.6% of teachers compared to 75% of those who spent 1 hour (P=.003). Almost 85.5% of teachers who previously visited ophthalmologists had moderate to severe effects on their eye health due to online learning during the COVID-19 pandemic versus 75.8% of others who did not (P=.004).
Table 6

Effect of online learning on eye health based on teachers’ demographic data, teaching data, and position

FactorsEffect of online teaching using computer/tablet/phone on your eye healthp-value
Severe effectModerate effectNo effect
No%No%No%
Age in years      .001*
22-3512.6%2360.5%1436.8%
36-507432.3%11952.0%3615.7%
51-60926.5%1955.9%617.6%
Gender      .001*
Male1114.9%3547.3%2837.8%
Female7332.2%12655.5%2812.3%
Had chronic health problems?      .175
Yes2328.8%3746.3%2025.0%
No6127.6%12456.1%3616.3%
Daily hours spent on online teaching before the COVID pandemic      .005*
1 hour1230.8%2359.0%410.3%
2-5 hours1114.7%4053.3%2432.0%
> 5 hours1940.4%2246.8%612.8%
Not used4230.0%7654.3%2215.7%
Daily hours spent on online teaching after the COVID pandemic      .003*$
1 hour325.0%650.0%325.0%
2-5 hours3820.8%10356.3%4223.0%
> 5 hours4340.6%5249.1%1110.4%
The distance between you and the digital screen display while using the device      .082$
< 50 cm5434.0%8050.3%2515.7%
50 cm2922.3%7456.9%2720.8%
> 50 cm18.3%758.3%433.3%
Screen brightness while using the device      .170$
Low315.8%1157.9%526.3%
Normal6327.8%11651.1%4821.1%
High1433.3%2661.9%24.8%
Very high430.8%861.5%17.7%
The position of the eyes toward the screen      .648
Down a little2832.2%4248.3%1719.5%
Straight ahead5325.6%11656.0%3818.4%
A little higher342.9%342.9%114.3%
Have you ever visited an ophthalmologist?      .004*
Yes6034.7%8850.9%2514.5%
No2418.8%7357.0%3124.2%
Have you ever used moistening eye drops?      .847
Yes1020.8%3164.6%714.6%
No1022.7%2659.1%818.2%
Have you ever had eye surgery?      .273$
LASIK1426.9%2955.8%917.3%
Others111.1%888.9%00.0%
No6928.8%12451.7%4719.6%

Discussion

The COVID-19 pandemic has forced schools and universities worldwide to switch to online learning. Moreover, this was implemented to reduce the disease spreading among students, teachers, and the entire community. Online teaching has shown to be of great help to schools and universities during the COVID-19 pandemic. Prolonged hours spent on the device screen can harm the visual feedback process and posture control system, which will affect eye health. Moreover, during the home quarantine, the entertainment method for most of the society was by using screens or devices, whether to watch the news, watch series and movies, or even play digital games for long hours, which led to an increased risk of eye strain and fatigue. Eye fatigue has a wide range of visual symptoms like burning eyes, blurred vision, difficulty concentrating, tiredness, headaches, and soreness of the eyes [20]. In this study, the investigation of the effect of online education on eye health was detected by using an online education eye health scale and eye fatigue scale, which showed that online education harmed the eye health of teachers. In the current study, the participants were 301, and the result showed the majority effect on the female gender with 87.7% compared with the male gender with 75%. Also, there is a moderate to severe effect on eye health reported by 82.4% of teachers aged 51-60 years compared to 63.2% of those aged 22-35 years. Before the COVID-19 pandemic, this research found that most schoolteachers with a percentage of 46.5% had never used the online way of teaching. Moreover, during the pandemic, most schoolteachers have spent two to five hours daily on online teaching, with a percentage of 60.8%. Tawil et al. reported the use for more than five hours as a significant risk factor for digital eye strain [21]. On the other hand, Ahuja et al. stated that a digital device used for more than five years with six hours of continuous use is a significant risk factor for eye strain, and subjects in this study have spent less than three years of continuous use of digital screens with the majority spending two to five hours only [22]. Other factors contributing to the effect of screens on the eyes are, first, the distance between the eyes and the screen, where it was found that most schoolteachers, with a percentage of 54.8%, kept a close distance (less than 50 cm). The recommended screen distance by the American Optometric Association is 51 cm. Second, the American Optometric Association recommended the screen's brightness to be adjusted to around 100-150 cd/m2, and this research has found that most schoolteachers use average brightness. Third, the position of the eyes on the screen can have a considerable effect, and in this study, it was found that 68.8% have a straight-ahead position. Although the position recommended by the American Optometric Association is to adjust the monitor height so that the top of the screen is at or slightly below the eye level, Ahuja et al. have found that when the device is placed below the eye level, it causes more symptoms that accommodations and convergence might cause during near vision. While in this research, the majority had a straight-ahead position; this is in contrast to the observation made by Agarwal et al., where the eyes were placed above the screen level to decrease the complaints of eye strain [22]. As for the prior mentioned factors, the effect on the eyes can be significant. This study found that most schoolteachers (53.5%) had a moderate effect on their eye health. Most subjects have complained of stinging, burning, roughness of eyes and eye redness, excessive lacrimation, and blurring of vision with photosensitivity, which suggests eye dryness. Similar symptoms were found in a recent study by Nawaf Al Marzouki et al., who assessed the digital eye strain during COVID-19 lockdown in Jeddah [15]; this is in contrast to Tawil et al., who reported the shoulder and neck pain to be the most common complaint [21]. Ahuja et al. found the burning sensation of the eyes, dryness of eyes, watering, and itching to be the most common complaints [22]. Moreover, 52.2% of schoolteachers have reported headaches, which may suggest myopia. Regarding the frequency of symptoms, the majority rarely had the symptoms, with a percentage of 55.7%. However, 45.2% when having the symptoms grade it as moderate. In a 2016 study by Bostanci [23], exposure to digital screens worsened eye symptoms, and in a study on computer use and vision, Shantakuri reported that new eye symptoms appeared as time spent on digital screens increased, the most common are redness and burning [24]. In this study, 301 teachers developed new symptoms after introducing online education. The most common occurrences were 34.6% excessive tearing of the eyes, 34.6% blurred vision, and 32.9% photosensitivity. The results showed higher differences in gender for headaches, which indicates that female teachers are at increased risk. Furthermore, this is consistent with studies showing a higher score of somatic complaints in females [25]. On the other hand, the incidence of headache has been noted to have a significant relation with distance, especially if it is less than 50 cm; this is consistent with some studies highlighting that visual fatigue increases with shorter distances [26-27]. Regarding blinking, the results showed that 29.9% of teachers had an increased change in blinking during the pandemic while 57.5% had no change. Furthermore, blinking decreased among 12.6%, suggesting the continuous use of smartphones causes dry eye-related symptoms. When relating dry eye and age between our study and the literature, 43.5% complained of a feeling of dryness of the eye, and it has a significant association with increased age and corresponds to the prior study's findings [28-30]. On the other hand, the dryness of the eye shows a higher score among females, which correlates with other studies [30].

Conclusions

Our study shows a consensus on the importance and value of eye health and the effects of online teaching during the COVID-19 pandemic. There is a noticeable effect reflected in subjects’ symptomatology and complaints. This should prompt health authorities to provide better teaching equipment and accessibility to essential eye care gadgets to teachers. Furthermore, our study shows that increased online teaching hours, posture, and screen distance are the most influential factors in teachers’ eye health. Future studies should aim to understand and compare the effects of online and on-site teaching in different areas and on the national level.
  18 in total

1.  Computer vision syndrome.

Authors:  M Raja Rajan Madhan
Journal:  Nurs J India       Date:  2009-10

2.  Eyestrain in VDU users: viewing distance and the resting position of ocular muscles.

Authors:  W Jaschinski-Kruza
Journal:  Hum Factors       Date:  1991-02       Impact factor: 2.888

Review 3.  Computer vision syndrome: a review of ocular causes and potential treatments.

Authors:  Mark Rosenfield
Journal:  Ophthalmic Physiol Opt       Date:  2011-04-12       Impact factor: 3.117

4.  The visual display terminal issue: a consideration of its physiological, psychological and clinical background.

Authors:  F W Campbell; K Durden
Journal:  Ophthalmic Physiol Opt       Date:  1983       Impact factor: 3.117

5.  Prevalence of dry eye in the normal population in Jeddah, Saudi Arabia.

Authors:  Amal Bukhari; Radwan Ajlan; Husain Alsaggaf
Journal:  Orbit       Date:  2009

6.  Prevalence of dry eye among adult Chinese in the Beijing Eye Study.

Authors:  Y Jie; L Xu; Y Y Wu; J B Jonas
Journal:  Eye (Lond)       Date:  2008-02-29       Impact factor: 3.775

7.  Prevalence of self-reported computer vision syndrome symptoms and its associated factors among university students.

Authors:  Layan Al Tawil; Sara Aldokhayel; Leena Zeitouni; Tala Qadoumi; Siham Hussein; Shaik Shaffi Ahamed
Journal:  Eur J Ophthalmol       Date:  2018-11-26       Impact factor: 2.597

8.  Prevalence and risk factor assessment of digital eye strain among children using online e-learning during the COVID-19 pandemic: Digital eye strain among kids (DESK study-1).

Authors:  Amit Mohan; Pradhnya Sen; Chintan Shah; Elesh Jain; Swapnil Jain
Journal:  Indian J Ophthalmol       Date:  2021-01       Impact factor: 1.848

9.  Community Transmission of Severe Acute Respiratory Syndrome Coronavirus 2, Shenzhen, China, 2020.

Authors:  Jiaye Liu; Xuejiao Liao; Shen Qian; Jing Yuan; Fuxiang Wang; Yingxia Liu; Zhaoqin Wang; Fu-Sheng Wang; Lei Liu; Zheng Zhang
Journal:  Emerg Infect Dis       Date:  2020-06-17       Impact factor: 6.883

10.  Digital eye strain in the era of COVID-19 pandemic: An emerging public health threat.

Authors:  Sudip Bhattacharya; Sheikh Mohd Saleem; Amarjeet Singh
Journal:  Indian J Ophthalmol       Date:  2020-08       Impact factor: 1.848

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