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Webster 1913 Edition
Horopter
Ho-rop′ter
,Noun.
[Gr. [GREEK] boundary + [GREEK] one who looks.]
(Opt.)
The line or surface in which are situated all the points which are seen single while the point of sight, or the adjustment of the eyes, remains unchanged.
The sum of all the points which are seen single, while the point of sight remains unchanged, is called the
horopter
. J. Le Conte.