Transorbital alternating current stimulation modifies BOLD activity in healthy subjects and in a stroke patient with hemianopia: A 7 Tesla fMRI feasibility study.

•Repeated daily application transorbital ACS to patients with optic nerve damage restores vision partially.•This feasibility study evaluated whether transorbital ACS modulates BOLD activity in early visual cortex in healthy subjects and in a patient with hemianopia.•In healthy subjects transorbital ACS increased the activated visual cortical surface area, decreased the fMRI response amplitude and increased coherence.•In the patient, BOLD amplitudes and coherence values were increased in most early visual areas in both hemispheres.