We assessed visual function after recovery from optic neuritis in 15 consecutive patients using five objective tests: colour vision testing with Ishihara colour plates and with D15 colour desaturated spots, Humphrey automated perimetry, contrast acuity testing with Regan letter charts and testing of visual evoked response (VER). Recovery of visual function was not found to be dependent on presenting Snellen visual acuity or treatment with oral steroids. The most sensitive measures of residual visual deficit were mean defect on automated perimetry, low-contrast acuity and VER.