Because MS patients frequently report visual acuity disturbances, neuropsychologists often screen patients for severe visual acuity disturbances and tailor test batteries that minimize the need for intact vision. Less is known about how mild visual acuity disturbances may influence neuropsychological test performance. This study examined the extent to which mild visual acuity disturbances influence performance on visually-based tests of complex attention. Relapsing-remitting and secondary progressive MS patients who reported adequate vision were recruited for this study. A battery was administered that included the oral version of the Symbol Digit Modalities Test (SDMT), the Visual Elevator (VE) subtest from the Test of Everyday Attention, and a reduced near vision eye chart. Results suggested that, in addition to measuring higher order cognitive processes, visual tests of attention are sensitive to mild primary visual disturbances in MS. (JINS, 2007, 13, 544–548.)