Emmetropia

For corrective lenses used to get someone to 20/20 vision, see 20/20 correction.

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.