Acuity card tests of 11 patients with cerebral visual impairment, unexplained by clinical and electrophysiological ophthalmic examinations, confirmed the suspicion of severe visual impairment in all but one patient, but resulted in acuity estimates higher than previous evaluations for all nine of the patients for whom an estimate could be made. Relatively good inter-test agreement supports the use of acuity cards for the quantitative evaluation of the vision of these patients.