Difference between revisions of Emmetropia
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Babies are born [[farsighted]], and become emmetropic over time after birth through [[axial elongation]] during emmetropization. | Babies are born [[farsighted]], and become emmetropic over time after birth through [[axial elongation]] during emmetropization. | ||
==Thresholds== | |||
Eyes are generally regarded as emmetropic if their spherical equivalent is between -0.5 and +0.5 D and can achieve 20/20 distance [[visual acuity]] without lenses. This permits some [[myopia]], [[hyperopia]], and [[astigmatism]]. | |||
==References== | ==References== | ||
Revision as of 18:47, 9 February 2022
Emmetropia is the state in which an eye is neither nearsighted nor farsighted nor astigmatic. An eye is said to be emmetropic when the image of an object at infinity (parallel light rays) forms on the retina, rather than in front of or behind it, implying it is free of astigmatism.
Babies are born farsighted, and become emmetropic over time after birth through axial elongation during emmetropization.
Thresholds
Eyes are generally regarded as emmetropic if their spherical equivalent is between -0.5 and +0.5 D and can achieve 20/20 distance visual acuity without lenses. This permits some myopia, hyperopia, and astigmatism.