The study was designed to measure dynamic visual acuity (DVA) during head movement as an assessment of the functional impact of vestibular deficits. The study design was a prospective, clinical study. The study was performed in a tertiary, ambulatory referral center. Forty-two normal subjects, 29 patients with unilateral vestibular loss, and 26 patients with bilateral vestibular hypofunction who were 19-87 years of age were examined. Diagnostic intervention was performed. Main outcome measures included the reliability, sensitivity, and specificity of a computerized test that measures visual acuity during head movement in normal subjects and in patients with vestibular deficits. The computerized DVA test was reliable in both normal subjects (intraclass correlation coefficient [ICC] r=0.87) and in patients with vestibular deficits (ICC r=0.83). The sensitivity of the DVA test was 94.5% and the specificity was 95.2%. The positive predictive value (individuals who test positive on the DVA test who will have a vestibular deficit) was 96.3%. The negative predictive value (individuals who test negative on the DVA test who will not have a vestibular deficit) was 93%. The computerized DVA test is reliable and is able to distinguish among normal subjects and patients with vestibular deficits.