noun
: the point taken as the position of the eye in calculations of optical instruments ; specifically : the optical center of the cornea-lens system as backed by the vitreous humor
noun
: the point taken as the position of the eye in calculations of optical instruments ; specifically : the optical center of the cornea-lens system as backed by the vitreous humor
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012