Fig. 8. Pupillograms of a patient with a left relative afferent pupillary defect. In the top tracings, it is apparent that the right and left pupil light reflexes resulting from a bright stimulus light applied to the right eye are substantial, compared with the lesser response of the two pupils when light is applied to the damaged eye. In the middle and bottom tracings, the light stimulus is reduced to the normal eye in an effort to reduce the amplitude of the pupillary contractions until they are balanced, or equal, when the light is alternated between the two eyes.