Background: The iris is a dynamic organ in which the autonomic nervous system regulates the activity. Iris activity reflects physiological reactions to different sensory stimuli, resulting in a variation in pupil size. There are many different diagnostic tools which assess iris activity. The present paper reviews the methods of pupillary assessment as a research tool and in clinical use.
Material and methods: The basis for this paper was obtained by searches on Medline and ISI Web of Knowledge. Reference lists were further checked for other relevant studies.
Results and interpretation: Pupillometry is a research tool that is adopted in an increasing number of medical fields. In the past this method was used mostly within ophthalmology and neurology; today it has spread to a wide range of medical fields, for instance pharmacology and physiology. There are continuous improvements in the flexibility and recording capacity of pupillometers and they are used in an increasing number of medical fields, though they are still most useful within research.