PRESBYTIA
\pɹɪsbˈɪʃə], \pɹɪsbˈɪʃə], \p_ɹ_ɪ_s_b_ˈɪ_ʃ_ə]\
Definitions of PRESBYTIA
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A very high degree is termed Hyperbresby'tia. A condition of vision, common in old persons, which consists in the circumstance of near objects being confusedly seen, whilst those at a greater distance are clearly distinguished. It is supposed to depend generally on diminution of the convexity of the cornea; whence results an alteration in the convergency of the rays, so that they form a focus behind the retina. This defect is remedied by the use of convex glasses, which augment the convergence of the luminous rays. It is, also, called Long-sightedness, Far-sightedness, Parop'sis Iongin'qua, Dyso'pia proximo'rum.
By Robley Dunglison
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