Refractive disorders of the eye

Vision impaired by refractive errors

Nature

Refractive disorders of the eye are common visual problems caused by irregularities in the eye’s ability to focus light accurately onto the retina. This results in blurred or distorted vision. The main types include myopia (nearsightedness), hyperopia (farsightedness), astigmatism (imperfect curvature of the cornea or lens), and presbyopia (age-related loss of near focus). These disorders stem from anatomical variations such as eyeball length, corneal shape, or lens flexibility. If uncorrected, refractive errors can impair daily activities and significantly reduce quality of life, making their identification and correction a widespread public health concern.

Background

Refractive disorders of the eye emerged as a recognized global health problem with the rise of industrialization and literacy, when increasing demands for near-vision tasks brought widespread visual impairments to attention. Epidemiological studies throughout the 20th and 21st centuries, including the WHO's Vision 2020 initiative (https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment), have highlighted their pervasive impact, especially in low-resource regions, catalyzing coordinated international efforts to quantify and address uncorrected refractive error.