Dynamic Visual Acuity

Dynamic Visual Acuity: the examiner can use screen-sharing to provide a visual acuity chart. Instruct the patient to sit at the appropriate distance from their screen at which the lowest line on the visual acuity chart is just readable. Have the patient move their head (horizontally to evaluate the horizontal SCC and vertically to evaluate the anterior and posterior SCC function) at ~2 Hz while viewing the chart. A decrease in best-corrected acuity of 2 lines or more from baseline is considered abnormal - patients with unilateral vestibular loss may loss 2-3 lines prior to compensation, while patients with bilateral vestibular loss will often lose 4 or more lines. Encourage the patient to keep moving their head throughout, as patients may have a natural tendency to slow or interrupt their active head movements in order to best visualize the target.