( n. )
An instrument for measuring the limits of distincts vision in different individuals, and thus determiming the proper focal length of a lens for correcting imperfect sight.
( n. )
An instrument for measuring the limits of distincts vision in different individuals, and thus determiming the proper focal length of a lens for correcting imperfect sight.
Webster's Revised Unabridged English Dictionary. Пересмотренный полный словарь английского языка Webster. 2012