What is ametropia?

Ametropia is the medical term for the presence of refractive error in the eyes. It occurs when the eye is not able to focus light rays from an object directly onto the retina to provide a clear image. Ametropia includes refractive error due to myopia, hyperopia and astigmatism.

Refractive errors occur when the eye cannot focus light rays from a distance object directly onto the retina. In myopia (nearsightedness), the light rays come to a focus in front of the retina. In hyperopia (farsightedness), light rays come to a focus behind the retina. In astigmatism, light rays focus at several different points, instead of at a single point. 

How does ametropia affect people’s lives around the world?

Ametropia is the most common eye problem in people of all ages around the world.  A recent review of vision impairment and blindness around the world found that uncorrected refractive error was responsible for visual impairment in more than 100 million people worldwide. Blindness was found in nearly 7 million people. This is the equivalent of nearly one in 100 people in the world with decreased or lost vision due to ametropia.   

Uncorrected ametropia has countless negative outcomes for individuals, their families and society in general. Poverty and poor access to eye care prevent many people around the world from receiving treatment to correct their refractive error. This has a ripple effect of decreased socioeconomic status for these individuals and their families. Education and employment opportunities become limited for those who suffer from ametropia.

Thanks to increasing awareness and medical outreach, the prevalence of visual impairment and blindness due to ametropia decreased by nearly one third from 1990 to 2010.

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