noun that refractive condition of the eye in which the rays of light are all brought accurately and without undue effort to a focus upon the retina;
opposed to hypermetropia, myopia, an astigmatism.
noun that refractive condition of the eye in which the rays of light are all brought accurately and without undue effort to a focus upon the retina;
opposed to hypermetropia, myopia, an astigmatism.
Webster English vocab. Английский словарь Webster. 2012