<prompt> All are true regarding optic neuritis except:Decreased visual acuityDecreased pupillary reflexAbnormal electroretinogramAbnormal visual evoked response retinogram  <response>: Electroretinogram indicates the activity of retinal esp. rods cones function and has no role in assessing the functional integrity of the optic nerve. So it can;t be abnormal in optic neuritis. Ref: AK khurana 7th ed. 