What is "presbytia"

Presbyopia \Pres`by*o"pi*a\[NL., from Gr. ? old, n., an old man + ?, ?, the eye.] (Med.) A defect of vision consequent upon advancing age. It is due to rigidity of the crystalline lens, which produces difficulty of accommodation and recession of the near point of vision, so that objects very near the eyes can not be seen distinctly without the use of convex glasses. Called also presbytia.

n. presbyopia.