Pulfrich Phenomenon

Pulfrich Phenomenon

The Pulfrich phenomenon is the observation that a pendulum swung from side to side appears to traverse a curved trajectory. This is a stereo-illusion resulting from latency disparities in the visual pathways, most commonly seen as a consequence of conduction slowing in a demyelinated optic nerve following unilateral optic neuritis.

References

Diaper CJ. Pulfrich revisited. Survey of Ophthalmology 1997; 41: 493-499 Rushton D. Use of the Pulfrich pendulum for detecting abnormal delay in the visual pathways in multiple sclerosis. Brain 1975; 98: 283-296

Cross References

Phosphene; Relative afferent pupillary defect (RAPD)