Impaired critical flicker frequency in recovered optic neuritis.

Thirteen patients with optic neuritis who recovered normal visual acuity and kinetic perimetry all showed impairment of foveal critical flicker frequency, a psychophysical test of visual temporal resolution. Because the magnocellular visual system demonstrates higher temporal resolution than the parvocellular system, this finding implicates involvement of axonal projections of magnocellular retinal ganglion cells in recovered optic neuritis.