Understanding Visual Processing After Occipital Stroke

Inclusion Criteria: * Residents of the United States or Canada * MRI and/or CT scans showing unilateral stroke or stroke-like damage to primary visual cortex or its immediate afferent white matter sustained 1-year or more prior to enrollment * Reliable visual field defects in both eyes as measured by Humphrey, Macular Integrity Assessment (MAIA), Goldmann, and/or equivalent perimetry. This deficit must be large enough to enclose a 5-deg diameter visual stimulus. * Ability to fixate on visual targets reliably for 1000ms (as demonstrated by visual fields, and verified in study participation) * Willing, able, and competent to provide informed consent * Cognitively able to understand and respond to written and oral instructions in English Exclusion Criteria: * Past or present ocular disease interfering with visual acuity * Corrected vision worse than 20/40 in either eye * Presence of damage to the dorsal Lateral Geniculate Nucleus * Diffuse, whole brain degenerative processes * Brain damage deemed by study staff to potentially interfere with testing ability or outcome measures * Documented history of traumatic brain injury * Documented history of drug/alcohol abuse * Current use neuroactive * Cognitive or seizure disorders * Subjects with one-sided attentional neglect