The internet has been widely used in 2020, with internet usage in Indonesia reaching 26.09% of active internet users, where the largest overall internet user is in Kalimantan at 21.27%. With internet usage, there will certainly be an increase in time spent in front of Video Display Terminals (VDTs) which are usually monitor screens such as laptops. Increased use of VDTs can cause various health problems that are not only visual problems but can also cause musculoskeletal problems such as Computer Vision Syndrome (CVS) [1]. CVS is a common phenomenon among digital device users. More than 90% of laptop users experience symptoms in their vision, such as blurred vision, tired eyes, ocular discomfort, dry eyes, dizziness, and when looking at close distances after using a computer, where these symptoms are symptoms of CVS. CVS is also known as digital eye strain or visual fatigue caused by continuously being in front of various types of laptops or other types of digital screens. The causes of CVS are divided into three categories: visual symptoms, symptoms from the digital screen itself, and symptoms resulting from the ocular surface. CVS encompasses a variety of nonspecific symptoms such as eyestrain, eye strain, blurred vision, pain around the eyes, double vision or diplopia, and headaches. Eye fatigue (asthenopia) and dry eyes are the main symptoms of CVS. These complaints can be linked to the use of Visual Display Terminals (VDTs), which are devices classified as VDTs, namely the screen monitors on electronic devices such as laptops, smartphones, tablets, and so on. According to research by Fadilah and Maharsi, CVS-related complaints are experienced by 85% of students who work in front of laptops [1]. CVS symptoms can be exacerbated by factors such as inadequate digital device use. The prevalence of visual symptoms increases significantly among those using laptops in inadequate lighting [2].

In general, workspaces with VDTs use brighter lighting. Furthermore, Research by Armin and Herlina found that 93% of respondents experienced CVS, such as eye fatigue. This was due   to   the   respondents’   habit  of   working   with inadequate laptop lighting or bright light [3]. Using a bright laptop can cause glare and reduce the eyes’ ability to focus their vision on the monitor. So the monitor's brightness must be balanced with the surrounding space. Generally, the lighting level is 300-500 lux. This complaint was also experienced by students of the Faculty of Medicine in a study conducted by Ananda and Eri, which found that 85% of them had tired eyes, then 52.1% had dry eyes, 62.9% had blurred eyes, 63.6% had headaches, 47.1% had sore eyes, 53.6% had watery eyes, 29.3% had double vision, and 45.7% had difficulty focusing their vision [4].

This study is quantitative and cross-sectional. This study aims to investigate the dynamics between risk factors and outcomes by using and collecting data. Each sample or subject is observed, and measurements are made of the subject's character status or variables at the time of examination. The population in this study consisted of undergraduate students of the Faculty of Medicine, Muhammadiyah University of Semarang, in the 2023 academic year. This study sample consisted of 128students from the Faculty of Medicine at Muhammadiyah University of Semarang, using simple random sampling from the population.

Table 1 shows that the most respondents had an ideal distance of 81 people 63.3%, while 47 36.7% had a distance that was not ideal. Most  respondents  had   ideal  room lighting 95 people, 74.2%, and 33 people 25.8% had non-ideal lighting. Most respondents were students whose laptop brightness was ideal 84 people, 65.6%, and those whose brightness was not ideal were 44 people 34.4%. Most respondents were students whose body position was not ideal 90, 70.3%, and those whose body position was ideal were 38 29.7%. Most respondents were students whose eye angles were not ideal 87, 68%, and 41 32% had ideal eye angles. Most respondents were students who experienced CVS 57% and those who did not 43%.

Table 1: Respondent Characteristics

Table 2 shows that the most common symptom of CVS was headaches, reported by 89 students 69.5%, while the fewest reported seeing colored halos around objects, reported by 10 students 7.8%.

Table 2: Characteristics of CVS Symptoms

Bivariate Analysis

Based on Table 3, the p-value = 0.001 (p<0.05); H0 is rejected. Therefore, there is a significant relationship between screen distance and the occurrence of CVS among students of the Faculty of Medicine, Muhammadiyah University of Semarang.

Table 3: Results of the Test of the Relationship between Screen Distance and CVS Incidents

Table 4 shows that the p-value is 0.781 (p>0.05); therefore, H0 is accepted. Therefore, there is no significant relationship between room light levels and the incidence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang.

Table 4: Results of the Test of the Relationship between Room Light and the Occurrence of CVS

Table 5 shows that the p-value is 0.597 (p>0.05); therefore, H0 is accepted. Therefore, there is no significant relationship between laptop brightness and the incidence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang.

Table 5: Results of the Test of the Relationship between Laptop Brightness and CVS Incidents

Table 6 shows that the p-value is 0.647 (p>0.05); therefore, H0 is accepted. Therefore, there is no significant relationship between body position and the incidence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang.

Table 6: Results of the Test of the Relationship between Body Position and the Occurrence of CVS

Table 7 shows that the p-value is 0.647 (p>0.05), so H0 is not rejected. Therefore, there is no significant relationship between body position and the incidence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang.

Table 7: Results of the Test of the Relationship between Body Position and the Occurrence of CVS

 Based on Table 8, the multivariate logistic regression results show that the most influential independent variable for CVS is the angle of the eye, with an Exp (B) value of 0.282, compared with the distance of the monitor screen.

Table 8: Results of the Multivariate Analysis of the Causes of CVS Events

Based on Table 3, the screen distance on the monitor when using a laptop is significantly associated with the occurrence of CVS, with a p-value of 0.001 among students of the Faculty of Medicine, Muhammadiyah University of Semarang. This result was also obtained in a study by Aulia Haydar, which found a less-than-ideal distance from the monitor screen among students of the Faculty of Medicine, Sultan Agung University of Semarang, with a p-value p 0.02 [5]. This is because insufficient distance from the monitor screen can cause contraction of the ciliary muscle, which can lead to asthenopia, blurred vision, and dry eyes [6].

Based on Table 4, the lighting in the room when using a laptop is not associated with the occurrence of CVS among students of the Faculty of Medicine, Muhammadiyah University of Semarang, with a p-value of 0.781. These results are in line with the Research of Srilalilun et al., which found no significant relationship with room lighting (p = 0.09). This study supports the conclusion that the occurrence of CVS is mainly influenced by the duration factor [7].

Based on Table 5, laptop brightness is not associated with the occurrence of CVS among students from the Faculty of Medicine, Muhammadiyah University of Semarang. The p-value is 0.597. This is consistent with Hassan Gadain’s Research, which found no significant relationship between brightness and the incidence of CVS (p = 0.174). This is supported by Research by Srilaluin et al., which stated that the duration of laptop use primarily influences the incidence of CVS.

Based on Table 6, body position when using a laptop is not associated with the occurrence of CVS among students of the Faculty of Medicine, Muhammadiyah University of Semarang (p = 0.647). The results of this study are in line with Research conducted by Aulia Haydar, which found no significant relationship between body position and the occurrence of CVS (p = 0.493). This is supported by Srilaluin’s Research, which shows that the duration of laptop use mainly influences the occurrence of CVS.

Based on Table 7, the angle of the eyes when using a laptop is associated with the occurrence of CVS among students of the Faculty of Medicine, Muhammadiyah University of Semarang, with a p-value of 0.003. The results of this study are in line with Research conducted by Debby et al., which has a p-value of 0.047. This is because if the angle of the eyes is higher than 10 °, it requires a chin-up posture with tension produced by the trapezius m.

• Among the students of the Faculty of Medicine, Muhammadiyah University of Semarang, it was found that the most common CVS complaints were headaches and the least were colored halos around objects

• The distance to the laptop monitor screen can affect the occurrence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang

• Room lighting does not significantly affect the incidence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang

• brightness does not affect the occurrence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang

• Body position when using a laptop does not affect the incidence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang

• The angle of the eyes when using a laptop does not affect the occurrence of CVS in students of the Faculty of Medicine, Muhammadiyah University of Semarang

Conflicts of Interest

The author declares that there is no conflict of interest related to the publication of this article.

Acknowledgment

The authors would like to thank the Faculty of Medicine, Muhammadiyah University of Semarang, for granting permission and providing full support for this Research. We also thank Wahyu Ratna Martiningsih, S.Ked., Andra Novitasari, S.Ked., and Swasty, S.Ked., as supervisors who provided invaluable guidance, support, and contributions in completing this Research. We also thank the Faculty of Medicine, Muhammadiyah University of Semarang, for providing facilities and support in completing this Research.

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