Causes of Myopia

People often say that the eyes are the windows to the soul—through them, we perceive all the beauty the world has to offer. Glasses-wearers are ubiquitous on city streets, many donning thick lenses daily. Over time, this can significantly affect one’s appearance and impose considerable inconvenience and limitations on daily life and physical activities. So, what causes myopia?

Causes of Myopia
Myopia typically arises from two main factors: genetics and environment. Decades of research indicate a definite genetic component to myopia. If both parents are myopic, their children face a substantially higher risk of developing myopia than children of non-myopic parents. Environmental factors also play a critical role—especially once the eye has matured. In the absence of strong genetic predisposition, environmental influences can greatly impact the onset and progression of myopia. Excessive near-work or prolonged close-up visual tasks (e.g., reading or screen use) may lead to loss of accommodation reserve, initially manifesting as “pseudo-myopia.” With adequate rest, this condition may improve; however, persistent strain over time can result in true, permanent myopia. This type is termed “physiological myopia,” usually not exceeding 600 diopters (D), and typically stabilizes after adolescence.

Myopia is one of the most common refractive errors. It occurs when, with the eye in a relaxed state, parallel light rays entering the eye focus *in front of* the retina rather than directly *on* it—resulting in blurred distance vision. During refraction testing, this refractive error is quantified as a negative value (e.g., −2.50 D). Based on severity, myopia is classified as mild, moderate, or high: mild myopia is ≤300 D; moderate myopia ranges from >300 D to 600 D; and high myopia exceeds 600 D.

We recommend patients avoid excessive eye strain and prolonged smartphone use. We hope this information proves helpful.