Global population, could be affected by high myopia by 2050

High myopia is a major global public health issue. It is defined as a refractive error of ≤ −6.00 diopters (D) or an axial length (AL) of ≥ 26.5 mm. This condition is one of the leading causes of irreversible visual impairment and blindness worldwide.

The prevalence of myopia, especially high myopia, is increasing rapidly. Current projections suggest that by 2050, nearly 1 billion people—approximately 9.8% of the global population—may be affected. The burden is particularly high in East Asian countries, where high myopia contributes significantly to social blindness.

The key feature of high myopia is excessive elongation of the eyeball, known as axial elongation. This abnormal growth results in structural and pathological changes that go beyond simple refractive error and may persist even after refractive surgery.

Common structural changes include thinning of the choroid, and diffuse choroidal atrophy. As the eye elongates, the retinal tissues become stretched and distorted—often compared to “pulled taffy”—which makes imaging and diagnosis more challenging. Clinically, an increase of just 1 mm in axial length can lead to approximately −3.00 diopters of additional myopia.

High myopia should be distinguished from pathologic myopia, although the two conditions frequently coexist. High myopia refers primarily to the severity of the refractive error. Pathologic myopia represents a more advanced and vision-threatening form of myopia that can result in permanent visual impairment.

High myopia is associated with numerous and serious complications that significantly increase the risk of vision loss. These complications include:

1-Glaucoma

2-Retinal Detachment

3-Cataracts

4-Dome-shaped Macula

5-Myopic Maculopathy

Environmental factors play a significant role in the rising global prevalence of myopia. Rapid urbanization, increasing academic demands, prolonged near work (such as reading and screen use), and reduced time spent outdoors all disrupt normal eye growth regulation.

The diagnosis and monitoring of high myopia and its associated complications have significantly improved with advances in imaging technology. Techniques such as spectral optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) allow detailed visualization of retinal and choroidal structures, enabling earlier detection.