This pilot study will test the preliminary efficacy and feasibility of an intervention protocol for one method of electric current stimulation, repetitive transorbital alternating current stimulation (rtACS), to treat visual impairment in people with glaucoma. We will evaluate a study protocol to use in future clinical trials to test the effectiveness of rtACS to ameliorate the progressive effects of vision loss both structurally and functionally in the eye, the visual pathway, and in regard to people's independence (i.e., functional ability). In this prospective, randomized controlled, double-masked pilot study, we will: 1) determine an effect of rtACS on ophthalmic structure and function (from retina to visual brain), 2) assess the methodology of procedures for assessment of people's functional ability and QoL to determine an effect of rtACS, and 3) assess the feasibility and implementation of the pilot study protocol for a larger multi-site, randomized controlled trial.