We read the article in the December 1996 issue of the Archives by Hofeldt and colleagues1 with considerable interest. Their finding that "baseball hitting was markedly affected by reducing light to one eye" is entirely consistent with the perception of an anomalous vector for an oncoming ball and would be consistent with the oblique stance and viewing angle. A mathematical appraisal of the phenomenon2 shows that when an object is approaching the observer in the midline or on the side of the eye with the reduced rate of conduction, it appears to veer toward the affected side (Figure).
The Pulfrich phenomenon is of particular significance in sports in which the participants are susceptible to orbital injury. In a series of 187 patients who had sustained injuries to the midface, we actively sought evidence of the Pulfrich phenomenon; we found 6 who manifested the disorder on account of presumed
Dutton GN, Heron G, Diaper C. Baseball Hitting and the Pulfrich Phenomenon: Could It Be Due to Traumatic Optic Neuropathy?. Arch Ophthalmol. 1997;115(10):1344-1345. doi:10.1001/archopht.1997.01100160514034