DIGITAL EYE STRAIN AND IT'S RELATIONSHIP WITH ACCOMMODATIVE DYSFUNCTION AMONG YOUTHS IN ENUGU

Digital eye strain (DES), also known as computer vision syndrome (CVS), refers to a state of ocular discomfort or visual disturbance linked to prolonged engagement with digital devices including computers, tablets, e-readers, and mobile phones. It is increasingly recognized as a public health issue stemming from multiple forms of stress on the ocular system (American Optometric Association 2022; Coles-Brennan, Sulley and Young 2019).

Computer vision syndrome has been acknowledged as a health concern for more than two decades. As the range of digital devices associated with these problems has expanded, terms such as digital eye strain (DES) and visual fatigue have gained preference, since many users do not classify tablets and smartphones as “computers” (Sheppard and Wolffsohn 2018). Other terms, including digital device syndrome (DVS) and smartphone vision syndrome (SVS), have also appeared in research, for instance by Hundekari, Sisodiya and Kot (2021).

There is a high frequency of visual complaints stemming from the visual stress of intensive near-work among computer users. Overall, as many as 90 percent of digital device users report experiencing symptoms of digital eye strain at some point (Lawrenson, Hull and Downie 2017; Mork et al. 2018; Rosenfield 2011). Seguí et al. (2015) estimated that 90% of the 70 million workers in the United States who use computers for more than three hours daily suffer from eye-related symptoms, making these complaints among the most common health issues reported by video display terminal (VDT) workers. Due to the dramatic rise in digital device usage in recent years, millions of people worldwide are at risk of developing DES. Although the symptoms are typically temporary, they can cause considerable and recurring discomfort. Despite affecting a vast number of individuals globally, the exact physiological mechanisms and underlying causes of DES are still not fully understood (Coles-Brennan, Sulley and Young 2019; Sheppard and Wolffsohn 2018).

Digital eye strain manifests through a collection of ocular symptoms, including eye strain, headache, tired eyes, tearing, general fatigue, blurred vision, burning sensation, red eyes, irritation, dry eye, foreign body sensation, double vision, and pain behind the eyes (Coles-Brennan, Sulley and Young 2019; Usgaonkar, Shet Parkar and Shetty 2021). The clinical term for eye strain is asthenopia, which broadly describes symptoms resulting from extended visual effort (Heus, Verbeek and Tikka 2018). Asthenopia literally denotes weakness or impairment of the eyes or vision, making it a suitable description for symptoms arising from visual or ocular disorders rather than solely external environmental influences (Evans 2007, p.16).

Symptoms of DES can be categorized into internal and external types. Internal symptoms are primarily linked to accommodation and binocular vision problems, such as blurred near vision, blurred distance vision after computer use, difficulty shifting focus between distances, headaches, and pain behind the eyes. External symptoms are more closely associated with dry eye manifestations, including burning sensations, irritation, tearing, eye strain, headaches, tired eyes, sensitivity to bright lights, and general eye discomfort (Sheppard and Wolffsohn 2018; Rosenfield 2011). Together, these symptoms constitute the condition known as computer vision syndrome or digital eye strain, arising from evaporative dry eye that compromises the ocular surface and from asthenopic symptoms due to sustained accommodation and convergence (Bahkir and Grandee 2020).

Internal symptoms related to accommodation and vergence issues generally result from prolonged focus on demanding near targets rather than the monitor itself. In contrast, dry eye symptoms appear more directly tied to computer use because of factors such as gaze angle, decreased blink rate, incomplete blinking, and surrounding environmental conditions (Rosenfield 2011).

1.2 Statement of the Problem

Although both digital eye strain and accommodative dysfunction are becoming increasingly common among young adults, the specific relationship between these two conditions is not well understood. There is a shortage of research exploring the link between digital eye strain and accommodative dysfunction, particularly within this age group. Consequently, there is a clear need for a thorough investigation into the potential association between digital eye strain and accommodative dysfunction among young adults (Rathi et al. 2017).

1.3 Research Questions

This study aims to answer the following questions:

1. What is the prevalence of digital eye strain among young adults who frequently use digital devices in Enugu?

2. What is the prevalence of accommodative dysfunction among young adults who frequently use digital devices in Enugu?

3. Is there a significant relationship between digital eye strain and accommodative dysfunction among young adults in Enugu?

1.4 Objectives of the Study

The main objectives of this study are:

1. To determine the prevalence of digital eye strain among young adults who frequently use digital devices in Enugu.

2. To determine the prevalence of accommodative dysfunction among young adults who frequently use digital devices in Enugu.

3. To investigate the relationship between digital eye strain and accommodative dysfunction among young adults in Enugu.

1.5 Significance of the Study

This research is important for illuminating the relationship between digital eye strain and accommodative dysfunction among young adults in Enugu. Greater understanding of these connections can assist healthcare providers, educators, and individuals in creating effective strategies to minimize the harmful effects of digital device use on visual health. The outcomes will add to the current knowledge base regarding the influence of digital screens on eye health and serve as a foundation for developing preventive measures.

1.6 Chapter Overview

The following chapters of this thesis will explore the subject of digital eye strain and its relationship with accommodative dysfunction among young adults in greater depth. Chapter 2 will present a detailed literature review, covering prior studies and relevant theories on digital eye strain and accommodative dysfunction. Chapter 3 will describe the research methodology, including the study design, participant selection, data collection methods, and statistical techniques. Chapter 4 will report the study’s findings, while Chapter 5 will offer an in-depth discussion of those results. Finally, Chapter 6 will summarize the research, highlight its contributions, and suggest directions for future studies.