1. That error of refraction in which rays of light entering the eye parallel to the optic axis are brought to a focus in front of the retina, as a result of the eyeball being too long from front to back (axial myopia) or of an increased strength in refractive power of the media of the eye (index myopia).
Also called nearsightedness, because the near point is less distant than it is in emmetropia with an equal amplitude of accommodation.
Origin: Gr. Myein = to shut
This entry appears with permission from the Dictionary of Cell and Molecular Biology
(11 Mar 2008)