(N.A.) Type: Term Definitions: 1. defined by the formula n sine a, where n is the refractive index of the medium between the object and objective lens and a is the angle between the central and the marginal rays entering the objective. Found on http://www.medilexicon.com/medicaldictionary.php?t=5355
(N.A.) Type: Term Definitions: 1. defined by the formula n sine a, where n is the refractive index of the medium between the object and objective lens and a is the angle between the central and the marginal rays entering the objective.