Nearsightedness, or myopia, is a prevalent refractive error that affects a significant number of individuals worldwide. Understanding the mechanism and various contributing factors behind myopia is essential for addressing this vision problem effectively. This article provides an in-depth overview of myopia, incorporating statistics and detailed information to shed light on its causes.

The World Health Organization (WHO) estimates that approximately 1.5 billion people had myopia globally in 2020. Myopia prevalence has been notably high in East and Southeast Asian countries, with rates exceeding 80% among young adults in urban areas of China. In Western countries, myopia prevalence has also been on the rise, with rates increasing from around 25% in the early 1970s to nearly 42% in the early 2000s among individuals aged 12 to 54 in the United States.

The primary mechanism behind myopia is the elongation of the eyeball. In individuals with myopia, the eyeball becomes longer from front to back, causing the light entering the eye to focus in front of the retina instead of directly on it. This elongation disrupts the normal optical pathway, leading to blurred distance vision. The exact causes of eyeball elongation are still under investigation, but genetic and environmental factors are known to play significant roles.

Genetic factors contribute to the development of myopia. Research indicates that if both parents have myopia, the likelihood of their children developing myopia increases. Multiple genes are believed to contribute to myopia susceptibility. Genome-wide association studies have identified several genetic variants associated with myopia risk. These variants are involved in processes related to eye growth, development, and signaling pathways. However, the interplay between genetic factors and environmental influences in myopia development is complex and not yet fully understood.

Environmental factors also play a role in the development of myopia. One significant factor is near work and eye fatigue. Prolonged engagement in activities such as reading, using digital devices, and performing close-up tasks can strain the eyes and potentially contribute to myopia development. However, the extent of the impact of near work on myopia is still a subject of ongoing research, as conflicting findings have been reported. It is believed that other environmental factors, such as lighting conditions, working distance, and posture during near work activities, may also influence myopia development.

The amount of time spent outdoors has emerged as a potentially protective factor against myopia, particularly in children. Spending at least 2 hours per day outdoors has been linked to a lower risk of myopia development. Outdoor time is thought to provide exposure to natural light, which may play a role in regulating eye growth and the release of neurotransmitters involved in refractive development. The specific mechanisms underlying the protective effect of outdoor time on myopia are still being investigated.

Poor visual habits have also been associated with myopia development. Holding reading materials too closely, inadequate blinking, and excessive eye rubbing can potentially contribute to the progression of myopia. These habits may lead to increased eye strain and potential changes in the shape of the eyeball. Encouraging healthy visual habits, such as maintaining proper reading distances, taking regular breaks during near work, and practicing good eye hygiene, may help reduce the risk of myopia.

Nearsightedness, or myopia, is a prevalent condition worldwide, with significant variations in its prevalence across different populations. Eyeball elongation, primarily due to genetic factors and influenced by environmental factors, is the main mechanism behind myopia. Genetic studies have identified various genes associated with myopia risk, but the interactions between genetics and environmental influences are complex. Near work, outdoor time, and visual habits all play a role in myopia development, but the specific impact and underlying mechanisms are still areas of ongoing research.

Understanding the mechanism and factors contributing to myopia can help inform preventive strategies, promote healthy visual habits, and guide personalized management. Regular eye examinations and consultation with eye care specialists are crucial for accurate diagnosis, early detection, and appropriate management of myopia