Introduction

Digital vision syndrome (DVS) is a medical condition, in which the patient suffers from a group of vision-related symptoms, chronic headaches, and other problems like neck and back pain due to prolonged exposure to digital screen (Altalhi, Khayyat, Khojah, Alsalmi, & Almarzouki, 2020). The use of computers and digital screens for more than three hours a day makes the person at high risk of developing DVS. The common ocular symptoms experienced in DVS are headache, dry eye sensation, blurred vision, tearing, burning, itching and photophobia (Basnet, Basnet, Karki, & Shrestha, 2018). The ease in using electronic devices as study materials over the hard copy has increased the prevalence of DVS among students (Iqbal, El-Massry, Elagouz, & Elzembely, 2018).

The nationwide mandatory curfew and “stay at home” orders imposed in response to the COVID-19 pandemic has made everyone to work from home and spend extra leisure time with screens. Due to this, the students are also forced to attend online lectures and study via digital gadgets as the provision to attend college or have access to the library has been denied. This has created an enormous spike in exposure time to mobile and other screens (Bhattacharya, Saleem, & Singh, 2020).

In this study, we have assessed the impact of COVID – 19 pandemic on prevalence, risk factors and the symptomatology DVS in a subset of medical students. The findings of this study would help in spreading awareness among the student community regarding the raising trend in DVS post lockdown.

Materials and Methods

This cross-sectional questionnaire-based study was conducted among 250 undergraduate medical students studying in Saveetha medical college, Chennai, Tamil Nadu. Non- medico students were excluded. The study participants were asked to fill an electronic semi-structured Google forms based questionnaire (Tawil et al., 2020).

The questionnaire was designed chiefly to obtain information regarding the amount and frequency of screen time exposure before and after lockdown and influence of lockdown on DVS symptomatology. A sample questionnaire has been attached (supplement). The data were interpreted and analysed using Statistical Package for Social Sciences (SPSS version 21.0). Descriptive statistical techniques were used to provide general details and responses. The relationship between variables was analysed using the chi-square test. The degrees of freedom (df) equals the number of values in a data set minus 1. The values obtained are expressed as percentage and number (within parenthesis).

RESULTS

Demographic data

The study included 250 undergraduate medical students comprising of 48.8% (122) male students and 51.2% (128) female students. The subjects selected for the study were aged above 18 years. Overall 29.2% (73) of the subjects were between 20 - 21 years of age, while 26.4% (66) and 25.2% (63) of the students belonged to the age group of 18-19 years and 22-23 years respectively. Only 19.2 % (48) of the students were above 23 years.

It was observed that 84% (210) of the respondents had refractive errors, and 16% (40) were devoid of refractive errors. Concerning the type of refractive errors present, it was noted that 33.6% (84) of the study subjects had hypermetropia, 24% (60) subjects were known to have myopia and 26.4% (66) of the subjects suffered from blurred vision (unknown refractive error). The results also depicted that 52.8% (132) of the students were wearing spectacles to rectify the refractive error. Almost 59.6% (149) subjects remained in curfew for more than four months period, while 30.8% (77) and 9.6% (24) of the students were under curfew for 3-4 and less than three months respectively.

Digital screen exposure

There was an increasing trend in the percentage of respondents with the exposure time of 2-3 hours [20.8%(52) to 26.8%(67)] and 3-4 hours [20%(50) to 30.8%(77)], whereas a decrease in percentage was observed in the category of 1-2 hours [29.2%(73) to 8% (20)].

But uncharacteristically, the percentage of respondents spending less than 1 hour per day on digital screen increased after lockdown [8.8% (22) to 14.8% (37)]. There was minimal change in the 4-6 hours [13.2% (33) to 12% (30)]and more than 6 hours [8% (20) to 7.6% (19)] categories. A Strong association was found between the total hours spent on digital screen before and during the lockdown at 1 % level (p = 0.000). Total hours spent on using the digital screen by the selected subjects (Pre and Post lockdown) is shown in Table 1.

The frequency of digital screen usage by the selected subjects (Pre and Post lockdown) is shown in Table 2.There was an increase in the number of respondents in the frequency of digital screen exposure in the "very often" [51.2%(128) to 52.4%(131)] and “continuous” [18%(45) to 21.2%(53)] categories. In contrast, a decreasing trend was observed in the "interrupted" [18.8%(47) to 18%(45)]and “rarely” [12%(30) to 8.4%(21)]categories following lockdown (Table 2). No Statistical association was found between the frequency of digital screen usage and the pre, post lockdown period (p=.508).

It was noted that the use of digital gadgets was more spread through the daytime [33.6% (84) to 38% (95)] than night time [37.6% (94) to 34.4% (86)] following lockdown. The relationship between the time of the day spent on a digital screen, and the before and during the lockdown was not statistically significant at 5 % level (p=.578). Time of the day spent on digital screen by the respondents (Pre and Post lockdown) is shown in Table 3.

Digital gadgets

There was a significant difference in the usage of mobile phones [51.2% (128) to 51.6% (129)]. The

use of laptop declined by 2% from 26.8% (67) to 24.8% (62). Tablets were used by 16% (40) post lockdown, while pre lockdown 12% (30) had used tablets. The use of desktop computers dropped from 10% (25) pre lockdown to 7.6% (19) post lockdown. But, the change in the use of digital gadgets was not statistically significant at 5 % level (p=.485). Type of digital screen used by the selected subjects (Pre and Post lockdown) is shown in Table 4.

Illumination refers to the brightness of the gadgets used. Light sensitivity can trigger dry eyes. Using the proper amount of illumination and the time of the day, we use digital devices to play a crucial role in protecting eyes. Irrespective of the digital devices used,35.6% (89) and 32% (80) preferred between 26% and 50% of illumination during the day and night time, respectively. Meanwhile, 25.2% (63) and 31.6% (79) chose 11%-25% illumination during day and night time respectively, followed by 22.4% (56) and 20%(50) opting for 51%-75% illumination in their digital screens during day and the night. Only around 8% and 10% of the respondents used the extremes of illumination (76%-100%) during day and night, respectively.

DVS symptoms

The respondents were asked to select one or more of the symptoms experienced by them from a list of symptoms before and during lockdown which included: Headache, fatigue, dry eyes, blurred vision, eye strain, double vision, eye redness/irritation, difficulty in refocusing the yes, lacrimal discharge in one or both eyes, neck/shoulder/back pain and none of the symptoms.

Of all, the headache was the most common symptom reported of DVS. The percentage of students having headache increased drastically after lockdown from 32.7% to 51.6%. There was a notable increase in eye strain from 19.5% to 40.3% and dry eyes from 10% to 21% during the lockdown as a consequence of the use of digital devices. Among the extraocular symptoms, neck, shoulder, or back pain was the most common symptom found in 18.2 % of students which increased to 35.2 % during the lockdown period. About 50.3% (80) did not experience any symptoms before lockdown, but the percentage dropped to 27.7% (44) during the lockdown. Almost 51% of the students felt that the mentioned symptoms intensified after lockdown (Figure 1).

Willingness to decrease screen time

Of the total participants, 87% of the participants observed a substantial impact of using the digital screen during this COVID-19 lockdown on eye health. Likewise, 92.8% (232) respondents were willing to decrease their screen hours to prevent their eye ailments.

DISCUSSION

The COVID-19 pandemic lockdown had sent humanity indoors, replacing human contact with an electronic connection (Munsamy & Chetty, 2020). Most colleges and workplaces have been forced to close, and the resulting use of alternative methods of teaching and studying has forced the screen time to increase drastically. This increased use of electronic devices and its influence has ascended a great concern on the health of the users. In this study, we aimed to assess the prevalence of DVS among undergraduate medical students during the COVID-19 lockdown.

Based on our study results, it was observed that there was a significant increase in the duration of digital screen exposure. An increasing trend was evident in the 2-3 and 3-4 hours category, although the rest of the categories did not show notable variation. But there was minimal changes observed in the 4-6 hours and more than 6 hours. Many studies imply that the duration of exposure to digital screen for more than 3 hours a day attributes to DVS (Munshi, Varghese, & Dhar-Munshi, 2017). Though the numbers are subjective based on an individual's response, our study highlights the fact that the screen exposure time has increased in the lockdown era.

There was no significant difference observed in the continuity of exposure or the type of digital gadgets used pre and post lockdown. It was also seen that mobile phones (pre lockdown: 51.2%, post lockdown: 51.6%) was the common digital gadget used, due to the convenience in handling.

In our research, the most commonly reported symptom was headache 32.7% before curfew, which shot up after the lockdown to 51.6%. According to the (American Optometric Association, 2017), the headache was the most widely reported DVS symptom which is trailed by eye strain and dry eyes (Hassan, Kashif, & Masud, 2017). Improper sitting and screen postures cause other muscular and skeletal problems (American Optometric Association, 2017; Logaraj, Madhupriya, & Hegde, 2014), as seen in our study where, the prevalence of neck, shoulder, or back pain increased from 18.2% to 35.2%. Many students had dry eyes which may be attributed to the reduced blinking reflex and improper tear production due to increased screen exposure (Abudawood, Ashi, & Almarzouki, 2020).

Around 60% of the students were in intensive lockdown, and (51%) of the students felt the increase in symptoms. Thus, the increase in symptoms shows relevance with the prolonged lockdown.

Since the students in this study were relatively young, they might have experienced symptoms only in severe cases.

Majority of the students (93.1%) felt that this lockdown served as a reason for increased digital screen usage and about (81.1%) students had an impression that this increased usage harmed their lifestyle and eye health during the curfew. Correspondingly 92.8%of the students were willing to decrease their screen hours to guard against DVS.

Conclusion

Limitations of this study include a cross-sectional study design conducted in a single institution, and DVS diagnosed based on self-reported symptoms without ophthalmic examination. As medical universities continuously reform their educational methods, there is a need to provoke awareness among students concerning their health effects allied to prolonged usage of computers and mobiles for studying. Preventive measures to reduce DVS associated symptoms should also be imparted. Intermittent exposure to digital screens with considerable refreshing breaks in-between online classes can be helpful. Online teaching classes can be scheduled 4-5 days a week instead of a daily basis. The students must be advised to monitor their screen time and maintain the same at lesser than 3-4 hours per day. Also, they must be well notified and hence be aware of the adverse effects of prolonged digital screen usage.

^{Acknowledgement}

The authors gratefully acknowledge the generosity of those who responded to the questionnaire for this study.

Conflicts of Interest

The authors have declared that there is no conflicts of interests.

Author Contribution

We declare that all of the authors mentioned in the article have contributed equal efforts in this research and also for the submission of the article.

Funding support

The authors declare that they have no funding support for this study.