## 1 Introduction  
The ubiquity of digital screens in modern life has transformed how individuals work, learn, and engage in leisure activities [1]. Over the past few decades, screen-based technologies have evolved rapidly, leading to an exponential rise in daily screen time across various demographics. Research highlights that screen exposure is no longer limited to traditional television and computer use but has expanded to smartphones, tablets, and wearable devices, contributing to a lifestyle dominated by digital interactions. Data from multiple global studies indicate that a significant portion of individuals, including children, exceed recommended screen time limits, with many accumulating more than six to eight hours of daily exposure [2]. This increase has been driven by technological advancements, the integration of screens into workplaces and education, and the convenience offered by mobile devices. However, while screens provide numerous benefits, including access to information and productivity tools, the shift towards prolonged digital engagement has raised concerns about its long-term health implications, particularly regarding sedentary behaviour and Digital Eye Strain (DES) [3; 4]. DES, or computer vision syndrome, is characterised by symptoms such as eye discomfort, headaches, blurred vision, and fatigue. The prevalence of DES surged during the COVID-19 pandemic, with studies reporting 80-94% of individuals experiencing symptoms, particularly those spending 7-10 h daily on screens [5]. Common long-term effects include dry eye disease, myopia progression, and potential retinal damage, exacerbated by reduced blinking rates and excessive near work. These issues affect productivity and well-being, highlighting the urgent need for preventive measures and awareness. A 2012 US survey found that 69% of adults used some method to track health indicators, with 60% monitoring weight, diet, or exercise. Those who tracked health were more likely to be older, non-Hispanic White, or African American and to have higher education. A total of 21% used technology for tracking, with many reporting that it influenced their health management and treatment decisions. This underscores the growing role of digital devices in health monitoring, especially as prolonged screen use increases concerns about DES, highlighting the need for advanced monitoring tools like eye-tracking technology [6]. Existing solutions, such as blue-light filters and ergonomic adjustments, aim to prevent eye strain but do not actively monitor or assess its effects. Eye-tracking technology offers a promising alternative, using metrics like fixations, saccades, and pupil responses to assess fatigue and mental workload [7]. These analyses offer insights into user fatigue levels, directly connecting to critical areas of interest such as reading comprehension and memory retention. Recent research has also explored how prolonged screen exposure affects the ocular surface, with studies indicating that high-energy visible (HEV) blue light emitted by digital screens contributes to corneal epithelial damage, oxidative stress, and inflammation [8]. These effects may exacerbate DES symptoms, particularly in individuals already susceptible to dry eye disease. Recent advancements in machine learning, including convolutional neural networks (CNNs) and generative adversarial networks (GANs), have improved eye-tracking accuracy for metrics including fixations and saccades [9]. Additionally, eye-tracking has been used to evaluate the impact of typography and typesetting on reading performance, with studies investigating whether font style, spacing, and text formatting influence eye strain, cognitive load, and reading efficiency [10]. This aspect is crucial, as typographic modifications are a widely accessible intervention that could enhance reading focus and retention. Nonetheless, there remains a notable gap in understanding the role of physical eye health and its direct link to overall fatigue with eye movement data.