Hippus is visible, rhythmic, but irregular pupillary oscillations that are deliberate in time. It comprises 2 mm or more excursions and has no localizing significance.

1. Normal
2. Incipient cataracts
3. Central nervous system diseases, including the presence of total third cranial nerve palsy, hemiplegia, meningitis (acute), cerebral syphilis, tabes, general paralysis, myasthenia gravis, tumors of corpora quadrigemina, epileptics, Cheyne-Strokes breathing, multiple sclerosis (disseminated sclerosis), and cerebral tumors
4. Neurasthenia (nervous exhaustion, Beard disease)
5. Drugs, including the following:
 

allobarbital amobarbital aprobarbital barbital butabarbital butalbital butallylonal butethal cyclobarbital

cyclopentobarbital heptabarbital hexethal hexobarbital mephobarbital metharbital methitural methohexital pentobarbital

pentylenetetrazol phenobarbital primidone probarbital secobarbital talbutal thiamylal thiopental vinbarbital

Fraunfelder FT, Fraunfelder FW. Drug-induced ocular side effects. Woburn, MA: Butterworth-Heinemann, 2001.

Zinn KM. The pupil. Springfield, IL: Charles C Thomas, 1972.