APA Dictionary of Psychology

n. nearsightedness, a refractive error due to an abnormally long eye: The retinal image is blurred because the focal point of one or both eyes lies in front of, rather than on, the retina. Specific types include chromic myopia, marked by blurred perception of distant objects; progressive myopia, a gradual loss of accommodation for distant vision associated with aging; and prodromal myopia, in which accommodation changes permit a return of normal sightedness after a period of myopia. Compare emmetropia; hyperopia.