Pupillometer (from lat. pupilla the pupil and the Greek. metreo " measure") - a device for measuring the width of the pupil. Direct measurement of the diameter of the pupil millimetre scale is complicated in connection with eye movements, fluctuations of the width of the pupil, caused by uneven lighting, the instability of the commit, and the action of a number of side inadequate stimuli exogenous and endogenous. The easiest pupillometer of Haab is a white plate coated with her black circles in diameter from 1 to 9 mm This record brings to the eye of the patient and compare the width of the pupil with black circles on the album. The accuracy of such a determination not more than 0,5 mm
For a more precise definition of the diameter of the pupil use methods of automatic registration of the width of the pupil (see Pupilographical).