The prevalence of computer vision syndrome and associated factors among university students in oman: a cross-sectional study

Abstract

Background

Computer Vision Syndrome (CVS) is among the most significant occupational risks of the 21st century, which impacts 70% of all computer users. The study is conducted in Oman to investigate the prevalence of CVS and the associated factors among university students.

Methods

This cross-sectional study included 293 undergraduate students from nine colleges and used an online self-administered questionnaire.

Results

The prevalence of CVS among the participants was 73.7%. The most reported extraocular eye symptoms were headache (52.4%) and eye strain and fatigue (45.7%). The results showed that students with uncomfortable seating postures and close-eye screen distance were twice as likely to develop CVS. Students who do not feel that digital technology affects their lifestyle and eye health and do not have a refractive error or wear glasses were less likely to develop CVS. The odds of CVS being present were less likely when consuming most of the screen time in social entertainment than when using the screen for university study.

Conclusion

This study found a high prevalence of computer vision syndrome that was significantly associated with uncomfortable seating posture, short screen distance, having no refractive errors, perception of minimal impact of digital technology on lifestyle, and using screens for entertainment. The study emphasized the necessity of considering the high prevalence of CVS and associated factors among university students. Therefore, academic institutions must implement comprehensive ergonomic strategies and healthy visual habits to avoid the occurrence of CVS.

Background

Computers significantly impact society and make work easier and more efficient [1]. Apart from their benefits, their use carries a risk of developing computer vision syndrome (CVS), an example of the world’s new issues with public eye health. CVS is among the most significant occupational risks of the 21 st century, which impacts 70% of all computer users [2]. Today, university students spend more time studying and conducting research while being constantly engaged with screens [3]. Computer users frequently experience ocular complaints, which may include double vision, blurred vision, eye strain, and a foreign body sensation [4].

According to the American Optometric Association, CVS is a disorder of the eyes and vision that results from prolonged use of computers, smartphones, e-readers, and tablets. CVS demonstrated a wide range of ocular and extraocular symptoms such as eye strain, blurred vision, dry eyes, redness, double vision, headaches, and neck or shoulder pain [2]. Between 64% and 90% of internet users are said to have CVS [4]. Moreover, around 60 million people worldwide are estimated to have CVS, and one million new cases are reported annually [2]. In addition, 95% of Saudi University students were found to have high prevalence of CVS [3]. Prolonged computer use and inappropriate lighting conditions lower the performance of the human vision system [2]. About 61% of computer-dependent workers experienced strained neck, shoulder, and lower back pain, while 70% reported eye strain [5]. In Oman, university students show high daily mobile phone usage, with many spending over six hours a day on academic tasks, social media, and entertainment—behaviors linked to eye strain, neck/back pain, and reduced classroom attention [6]. At another university, students reported using their smartphones mainly to stay informed, connect with others, and express themselves—factors that naturally lead to extended screen time [7].

Identifying the specific causes of CVS is challenging; however, several contributing variables, including extended work hours, insufficient breaks, posture, room lighting, screen filter usage, screen brightness, and excessive screen time, have been identified [2, 5]. A multi-directional approach is suggested to reduce CVS [2]. The best preventative strategies to decrease CVS are maintaining a recommended distance from the screen, taking regular breaks, using anti-glare filters, regulating ambient lighting, and changing the learning environment and teaching tools [8, 9].

Across the Middle East, multiple studies have reported a high prevalence of CVS symptoms, including eye strain, headaches, dry eyes, and neck or back pain. Countries like Jordan, Egypt, Saudi Arabia, and Libya document significant rates of digital eye strain among university students [10–16]. Despite Oman sharing similar digital habits and educational environments, there is a notable lack of research on CVS among university students. Only one study in Oman found that most students experienced symptoms such as eye strain, headaches, and musculoskeletal discomfort, mainly due to extended screen exposure and suboptimal ergonomics [17]. However, broader data on the prevalence and associated factors of CVS in the Omani student population remain scarce. This gap in the literature underscores the importance of the current study, which aimed to investigate the prevalence of CVS and identify its associated factors among university students in Oman.

Methods

Study design

A cross-sectional study using a descriptive associative design was used.

Setting

The study was conducted between mid-July and mid-August of 2023 at a public university comprising nine colleges and approximately 17,000 students. It included undergraduate students from nine colleges: Medicine and Health Sciences, Nursing, Economics and Political Science, Agricultural & Marine Sciences, Arts and Social Sciences, Engineering, Education, Science, and Law.

Sampling and sample size

Due to the logistical and time constraints of data collection, the convenience sampling method was used. The G*Power statistical software version 3.1.9.7 was used to calculate the sample size based on the most sophisticated test used in this study, logistic regression [18]. The required sample size is 213, with a significance level of 0.05, a power of 80%, and an odds ratio of 1.5. We increased the sample size by 10% to compensate for the missing data, resulting in a minimum required sample size of 235.

Inclusion and exclusion criteria

The study included male and female undergraduate students aged 18 years or older currently enrolled at the university. Students with known vision impairments (e.g., blindness) or those who have undergone ocular surgery were excluded, as reported by the students while completing the first questionnaire sheet.

Study instruments

The CVS Survey Form 3 (CVS-F3) was used to measure CVS. The Arabic version of CVS-F3 is valid and reliable among Arabs, with a Cronbach’s Alpha reliability coefficient of 0.742 [19]. Permission was taken from the authors of the study. The CVS-F3 includes 28 questions. It was originally developed from an earlier version (CVS-F1), which was tested on 100 medical students and validated using content validity. Although the instrument was first applied in Egypt, we assessed its suitability for the Omani university context through expert review. Specifically, the questionnaire was evaluated by two professionals, one a PhD holder in nursing and the other a practicing optometrist, who confirmed the content was relevant, culturally appropriate, and clearly understood by the target population. Given that Oman and Egypt share the same language (Arabic), and no cultural or contextual mismatches were identified by the experts, no modifications to the questionnaire were deemed necessary. The CVS-F3 consists of questions related to (1) total screen hours spent on a digital screen in 24 h and the version, types of, and most used devices, and (2) symptoms frequently occurring with screen use over the last 12 h; the symptoms are divided into eight ocular symptoms and seven extraocular symptoms. The ocular symptoms include blurred vision, eye dryness, eyestrain and fatigue, eye redness and irritation, double vision, difficulty refocusing the eyes, near vision discomfort, and difficulty distinguishing objects after screen use. On the other hand, the extraocular symptoms are headache, insomnia, depression, neck/shoulder/back pain, joint pain in fingers and wrists, inability to hold objects well, and difficulty writing using a pen; (3) associative factors illustrated from the questionnaire are using ergonomic practices related to poor screen- resolution or design, glare screen, lighting condition and screen brightness, seating postures, distance to the screen, and use of both thumbs on texting. The CVS Survey Form 3 is a self-report survey that used a symptom-based screening tool designed to identify CVS based on self-reported symptoms rather than numerical scoring. Therefore, the presence of CVS was documented if the participant presented at least one of the following primary criteria: (1) the presence of one or more ocular symptoms, (2) the presence of one or more extraocular symptoms, and (3) the presence of one or more attacks of ocular or extraocular symptoms every month over the last 12 months. This approach is consistent with previous studies that have employed this tool to identify the presence of CVS based on symptom occurrence.

Ethical considerations

The study was conducted in accordance with the ethical principles of the Declaration of Helsinki, as it involved research with human participants. Institutional ethical approval has been granted by the Research and Ethics Committee of the College of Nursing at the same public university (CON/GP/2023/1). The online data collection tool was distributed using Google Docs, which was identified as anonymous and allowed respondents to review their replies before submitting them. Before the data collection began, the study’s detailed information page, which included the study purpose, number of items, time required to complete it, and details regarding confidentiality, data preservation, and consent, were explained to all participants. Participants were assured that their participation was voluntary and that they had the freedom to refuse to answer any questions they felt uncomfortable answering and to withdraw from the study at any time.

Data collection procedure

The study team created a QR barcode for the questionnaire and delivered it to the participants face-to-face. The researcher visited the colleges with the QR code and met the students at each college, explaining the study and obtaining the initial consent for participation. If participants agreed, they were asked to scan the code and be directed to an online survey to begin completing the data and submitting their responses. This approach to data collection enabled the researcher to explain the study and ensure informed consent. At the same time, the QR-linked online survey minimized data entry errors and allowed participants to respond privately and conveniently, enhancing both participation and data quality. The survey was divided into four sections: Section One included study information and consent forms, Section Two contained demographic information, Section Three addressed CVS symptoms, and Section Four covered associated factors. Data collection was completed in one month (mid-July and mid-August 2023).

Data management and analysis

For this study, the data were analyzed using IBM SPSS, version 23. The demographics and overall results were reported using descriptive statistics, including means, standard deviations, frequencies, and percentages. Prior to conducting parametric analyses, the Shapiro-Wilk test was applied to assess the normality of continuous variables. The data met the assumptions for normality, allowing the use of parametric tests. Bivariate analysis was conducted for all individual factors and CVS using the t-test for continuous variables and the chi-square test for categorical variables. Significant associations were then entered into the logistic regression analysis to determine the associative factors of CVS. The Nagelkerke R-square was used to assess the model’s explanatory power, indicating how much variation in CVS prevalence could be explained by the included factors.

Results

Participants characteristics

The study included 293 participants with a mean age of 20.7 years (SD ± 2.1). The majority were female (57.0%), students from science colleges (57.3%), in their third academic year and above (73.0%), and had a grade point average (GPA) of 3 and above (62.0%) (Table 1).

Table 1.

Sample characteristics and distribution of CVS across groups

		Presence of CVS (Yes)	p-value
Variable	Frequency (%) (n = 293)	Frequency (%)
Sex
• Male	126 (43.0)	86 (68.3)	0.065
• Female	167 (57.0)	130 (77.8)
College
• Science colleges	168 (57.3)	118 (70.2)	0.116
• Humanity colleges	125 (42.7)	98 (78.4)
Academic year
• 2nd year and below	79 (27.0)	57 (72.1)	0.711
• 3rd year and above	214 (73.0)	159 (74.3)
Cumulative Point Average (GPA)
• 3 and above	182 (62.1)	136 (74.7)	0.617
• Less than 3	111(38.0)	80 (72.1)
Have refractive error or wearing glasses
• Yes	63 (21.5)	59 (93.7)	0.000*
• No	230 (78.5)	157 (68.3)
Digital screens affect lifestyle and eye health
• Yes	233 (79.5)	183 (78.5)	0.000*
• No	60 (20.5)	33 (55.0)
Screen-version of the most common screen used?
• New-version screen (within last 2 years)	215 (73.4)	161 (74.9)	0.452
• Old-version screen	78 (26.6)	55 (70.5)
The main purpose that consumes most of screen time?
• University Study	75 (25.5)	58 (77.3)	0.005*
• Social communication/Entertainment	119 (40.6)	76 (63.9)
• Both	99 (33.8)	82 (82.8)
Close eye-screen distance
• Yes	97 (33.1)	82 (84.5)	0.003*
• No	195 (66.6)	133 (68.2)
Uncomfortable seating postures
• Yes	174 (59.4)	145 (83.3)	0.000*
• No	119 (40.6)	71 (59.7)
Texting with both thumbs
• Yes	121 (41.3)	97 (80.2)	0.031*
• No	170 (58)	117 (68.8)

CVS Computer Vision Syndrome

*significant at p-value < 0.05; Chi-square test

Prevalence of CVS among university students

The overall prevalence of CVS was high, at 73.7% (Fig. 1), with the following demonstrating a higher prevalence of CVS: females (77.8%), students with a GPA of 3 or above (74.7%), students in the third year and above (74.3%), students in humanity colleges (78.4%) (Table 1). A chi-square test was conducted to examine associations between participant characteristics and the presence of CVS. No significant associations were found between CVS and sex, college type, academic year, GPA, or the screen version used. However, a significantly higher CVS prevalence (93.7%) was noted among participants with refractive errors or wearing glasses compared to those without (68.3%) (p <.001). Those who believed digital screens affect health were more likely to report CVS (78.5%) than those who did not (55.0%, p <.001). The purpose of screen use was also significant, with the highest prevalence among those using screens for both, study and entertainment (82.8%, p =.005). CVS was more prevalent among those reporting close eye-screen distance (84.5%, p =.003), uncomfortable seating posture (83.3%, p <.001), and texting with both thumbs (80.2%, p =.031) (Table 1). When asked about the symptoms, the most experienced extraocular symptoms associated with screen use were headache (52.4%), followed by neck, shoulder, and back pain (48.5%), and insomnia (35.2%). The most common ocular symptoms were eye strain and fatigue (45.7%), followed by dry eyes (25.9%) and difficulty refocusing the eyes (23.5%) (Table 2).

Fig. 1.

Presence of computer vision syndrome (CVS) among nursing students (n = 293)

Table 2.

Distribution of ocular and extraocular symptoms of CVS among participants (n = 293)

Type of symptom	Symptom	Frequency	Percentage
Ocular symptoms	Blurred vision	49	16.7%
	Eye strain and fatigue	134	45.7%
	Difficulty in refocusing the eyes	69	23.5%
	Dry eyes	76	25.9%
	Eye redness and irritation	63	21.5%
	Near vision discomfort/difficulty	32	10.9%
	Double vision/diplopia	14	4.8%
	Unclear object post-screen use	54	18.4%
Extraocular symptoms	Headache	153	52.4%
	Insomnia	103	35.2%
	Depression	60	20.5%
	Neck/shoulder/back pain	142	48.5%
	Inability to hold objects well	12	4.1%
	Joint pain in fingers and wrists	54	18.4%
	Difficulty to write using a pen	19	6.5%

Factors associated with cvs among university students

All variables with significant bivariate relationships with CVS were included in the logistic model. A logistic regression model was performed to examine the effects of uncomfortable seating postures, close-eye screen distance, the impact of digital screens on lifestyle, refractive error or wearing glasses, and the primary purpose that consumes most of the screen time in the presence of CVS. The overall model was found to be statistically significant (X² (8) = 77.044, p <.050). The model explained about 34% of the variance in CVS (Nagelkerke R-square). Those with uncomfortable seating postures and close eye screen distances were twice as likely to develop CVS (OR = 2.629, p <.050, 95% CI [1.40, 4.91]; OR = 2.461, p <.050, 95% CI [1.20, 5.03], respectively). Participants who did not feel that digital devices affected their lifestyle and eye health (OR = 0.333, 95% CI [0.16, 0.66]) and did not have a refractive error or wear glasses (OR = 0.111, 95% CI [0.03, 0.34]) were less likely to develop CVS. The odds of CVS presence will be less likely when consuming most of the screen time in social entertainment (OR = 0.431, 95% CI [0.20, 0.92]) compared to using the screen for university study purposes (Table 3).

Table 3.

Associative factors with CVS using logistic regression

		B	SE	Wald	df	Sig	Exp(B)	95% C.I. for EXP(B)
								Upper	Lower
Uncomfortable seating postures (Yes)		0.966	0.320	9.148	1	0.002**	2.629	1.405	4.917
Close-eye screen distance (Yes)		0.901	0.365	6.090	1	0.014*	2.461	5.034	1.204
Effect of digital screen on life (No)		−1.100	0.354	9.633	1	0.002**	0.333	0.667	0.166
Refractive error or wearing glass (No)		−2.195	0.580	14.344	1	0.000**	0.111	0.347	0.036
Purpose of consuming screen time (Social Entertainment)		−0.842	0.389	4.694	1	0.030*	0.431	0.923	0.201

Variable(s) entered on step 1: Texting with both thumbs, Uncomfortable seating postures (Yes), Close eye screen distance (Yes), Effect of digital screen on life (No), Refractive error or wearing glass (No), previous diagnosis of dry eye disease or use eye drops to treat it (No), Purpose of consuming screen time (Social Entertainment).

Abbreviations: CVS Computer Vision Syndrome, B Coefficients, SE Standard errors, df Degrees of freedom, Sig Significance values, CI Confidence Intervals.

This table includes the significant variables only; p <.05*, p <.01**

Discussion

The current study investigated the prevalence of CVS and the associated factors among university students. The study revealed that the prevalence of CVS among university students was 73.7%. Those with uncomfortable seating postures and close-eye screen distance were twice as likely to develop CVS. Participants who do not believe that digital devices affect their lifestyle and eye health, those without a refractive error or who wear glasses, and those who spend most of their screen time on social entertainment were less likely to develop CVS.

Prevalence of CVS

Regarding the prevalence of CVS, this result aligns with a study conducted among Spanish university students, which found CVS prevalence at 75% [20]. However, our findings were less than those of the study done in Thailand among Thai University Students, which reported a CVS of 81.0%. These differences could be correlated with the period of the Thailand study, as it was conducted in September 2021, which coincided with the duration of the third wave of the COVID-19 pandemic. Hence, the lectures and university tasks shifted from face-to-face to online, synchronous or asynchronous activities [21]. Compared to the current study, a study in Saudi Arabia reported a higher prevalence of CVS among health science students (97.3%) [22]. However, the methodology used to determine the presence of CVS could account for the high percentage of CVS. The Saudi study measured the presence of the syndrome by the appearance of one symptom without a specific duration or frequency [22]. In contrast, in our current study, participants were classified as having CVS only if they experienced at least one ocular and one extraocular symptom monthly over the past year. On the other hand, there was a lower prevalence of CVS reported in a study conducted at a Nigerian University, with a percentage of 54.3% [23]. In the Nigerian study, the lower prevalence reported could be due to the small sample (n = 153) and the use of different criteria that required the presence of symptoms, either intermittently or continuously, for at least one week within the last year [23]. Therefore, the reported prevalence of CVS varied depending on the study’s time, nature (online vs. traditional), sample size, and instrument used to measure CVS.

Significant associative factors of CVS

Ergonomics is the study of designing work systems that consider cognitive, organizational, physical, and environmental factors to optimize the interaction between humans and computers, thereby enhancing their well-being [5]. Eye screen distance, seating position, eye level, screen glare, and lighting conditions are ergonomic practices predisposing individuals to CVS. In our study, CVS development was twice as prevalent in those with close-to-eye screen distance and uncomfortable seating positions. Similarly, several studies have demonstrated a strong correlation between the possibility of CVS and close eye-screen distance [3, 5, 19, 23]. A study shows that using computers less than an arm’s and forearm’s length significantly increased CVS symptoms [3]. In addition, a study conducted at Mulawarman University in Indonesia found that 79.9% of respondents used a visual display terminal (VDT) with a screen size of less than 50 cm, which increased the risk factors for CVS symptoms by 1.654 times [24]. The explanation is that visual fatigue worsens as the distance between the person and the device gets shorter [3]. According to the American Optometric Association, the ideal viewing distance is between 16 and 30 inches [25]. Other study results reported that individuals who frequently sat with their backs bent were more likely to report CVS [26]. The reason is that the short space between the eye and the computer leads to more exposure to electromagnetic radiation from the computer [26]. In contrast, a study conducted among medical students in Saudi Arabia found no correlation between sitting posture and CVS [3].

According to the current study, 21.5% of participants with CVS had refractive errors or wore glasses. However, current findings showed that those without refractive error or not wearing glasses were significantly less likely to develop CVS. Numerous studies have demonstrated a significant correlation between CVS and refractive error. For example, a study conducted at the University of the West Indies in Jamaica found that 36.2% of the CVS participants had refractive errors [8]. Participants without refractive errors or those not wearing glasses were significantly less likely to develop CVS. This may be because people with refractive errors often experience more visual strain when viewing screens, especially if their vision is not adequately corrected. Digital screens require constant effort due to their brightness, pixelation, and changing content, which can increase the risk of eye fatigue. In contrast, individuals with normal vision can better maintain clear focus, reducing the likelihood of developing CVS symptoms [27]. Inconsistently, a study conducted in Saudi Arabia found no conclusive correlation between CVS and refractive error [3].

The current study’s findings showed that the presence of CVS was significantly less likely to occur when consuming screen time for social entertainment than for other purposes, such as studying. This outcome is inconsistent with a study done among university students in Spain [20]. Variations could be related to the differences in period and the intensity of visual and cognitive demands of the students’ tasks. In addition, it could be associated with the type of device used in study and leisure.

Moreover, the current study indicated that students who did not believe digital devices affect their lifestyle and eye health were less likely to develop CVS. However, no studies have been identified to report this relationship. The justification for the current study’s findings may be attributed to social desirability, where students reported what society wanted or what they wanted, as they were in favour of using screens in entertainment. Another reason could be attributed to the relationship between beliefs and attitude, so students would not exhibit or report the psychosomatic effects of CVS symptoms if they do not believe that the screen harms their health and eyes.

Study strengths and limitations

One of the study’s main strengths is its focus on the university student population in Oman, which is highly exposed to digital screens but often underrepresented in vision health research. By exploring a wide range of behavioral, ergonomic, and visual factors, the study offers a comprehensive view of CVS’s multifactorial nature. Moreover, the relatively large sample size and the inclusion of multivariate analyses enhance the study’s internal validity, supporting the applicability of the findings to similar academic contexts in the region.

One of the main limitations of our study is its restricted scope, resulting from the use of a cross-sectional study design and convenience sampling approach at a single university. This limitation restricts the generalizability of the findings to other student populations and does not preclude the possibility of a causal relationship or change over time. The prevalence of CVS was reported based on symptoms without an ophthalmic examination, which could lead to an over- or under-estimation of CVS prevalence. Additionally, it relied on self-reported symptoms, which could lead to an inaccurate perception of symptom severity due to recall bias. Another limitation is the lack of detailed screening for specific ocular conditions (e.g., uncorrected refractive errors, dry eye, or accommodative dysfunctions) that may predispose individuals to CVS. These unmeasured variables may have acted as potential confounders in the association between screen time and CVS symptoms.

Study recommendations and implications

CVS is a prevalent health issue affecting students’ academic performance. The high prevalence of CVS in our study, 73.7%, underscores the need to investigate the underlying causes of CVS, as this study did not account for the university environment and teaching methods. Therefore, continued research is necessary to identify the risk factors associated with CVS and to assess the knowledge, attitudes, and practices of CVS among students. To enhance students’ awareness, the current study recommends designing posters with safety guidelines for using digital screens and distributing them in classrooms, lounges, and other areas where students commonly congregate and on social media platforms. In addition, training sessions should be established to educate students about the importance of ergonomic practices, especially proper sitting positions and eye screen distance. In addition to implementing some adjustments in the classroom, such as using good-quality screens and specifying time for breaks in lectures with long durations. Future research should be conducted across multiple sites involving a larger, more diverse population and utilize objective clinical evaluation methods, such as ophthalmic evaluation, to confirm the presence of CVS, control confounding factors, and enhance generalizability.

Conclusion

In this study, the prevalence of CVS among university students is 73.7%. The significant associated factors with CVS were uncomfortable seating postures, close-eye screen distance, the effect of digital screens on lifestyle, refractive error or the need for glasses, and the primary purpose that consumes most of the screen time. Further studies are recommended to investigate these factors and their relationship with CVS, using longitudinal interventional studies with multiple sites to inform the development of strategies that prevent CVS among university students.

Authors' contributions

All authors contributed to the conceptualization, data curation, formal analysis, investigation, methodology, validation, writing, review, editing, and approval of final manuscript. H.A. and A.A. contributed to project management and supervision.

Funding

The author(s) received no financial support for this article’s research, authorship, and/or publication.

Data availability

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

The Research and Ethics Committee (CON/GP/2023/1) has granted institutional ethical approval. All participants provided written informed consent before enrolment in the study.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.