Pupil testing assesses the size, shape, and reactivity of the pupils to light and near focus, providing information about optic nerve and autonomic pathway function. It is a routine part of neurological and eye examinations.
Components
Clinicians observe baseline pupil size in light and dark, direct and consensual light responses, and near responses. Special tests, such as swinging flashlight testing, help detect relative afferent pupillary defects.
- Uses pen torches or slit-lamp beams for controlled illumination
- Differences in size, shape, or reaction may indicate underlying disease
- Testing can be adapted for unconscious or uncooperative patients
- Pharmacological tests may be used in selected cases to clarify causes
Clinical Role
Pupil findings assist in diagnosing optic neuropathies, third nerve palsies, Horner syndrome, and pharmacological effects. They are also important in acute settings such as head injury or suspected raised intracranial pressure.
- Changes from baseline can signal new neurological or ocular events
- Findings guide further imaging and urgent management when needed
- Documentation is essential for monitoring progression or recovery
- Pupil testing is interpreted alongside visual acuity and field results
