Repetitive Transcranial Alternating Current Stimulation (rtACS) for the Treatment of Optic Neuropathies

Inclusion Criteria: 1. Participant must be at least 18. 2. Clinical diagnosis of glaucoma, with Humphrey Visual Field 24-2 mean deviation (MD) between -22 dB and -5 dB, and Visual Field Index (VFI) between 10% and 90%. The visual field test at screening must meet the following reliability indices: * Fixation losses (FL) ≤ 33% * False-negative rate (FNR) ≤ 20% * False-positive rate (FPR) ≤ 20% At initial screening, the difference in MD between two consecutive visual field tests must be less than 2 dB. 3. Best-corrected visual acuity (BCVA) ≥ 0.2 in the worse eye selected for stimulation treatment. 4. If a participant has two eyes meeting study criteria, one eye will be randomly selected by computer for study participation. 5. In the opinion of the investigator the participant's eye pressure must be clinically stable. 6. Participant must has the ability to comply with the requirements of the study and complete the schedule of events. 7. Participant must understand and sign the informed consent. If the participant's vision is impaired to the point where he/she cannot read the informed consent document, the document will be read to the participant in its entirety. 8. Optical coherence tomography (OCT) imaging shows measurable changes in either peripapillary retinal nerve fiber layer (RNFL) thickness or macular ganglion cell-inner plexiform layer thickness. Exclusion Criteria: 1. History of ocular herpes. 2. Pathological nystagmus. 3. Retinal disease sufficient to affect vision. 4. Corneal opacity affecting vision. 5. Cataract affecting vision. 6. Uveitis or other intraocular inflammatory disease. 7. Implanted electronic devices such as a pacemaker. 8. Rheumatologic or autoimmune disease. 9. Brain tumor or intracranial magnetic metallic implants. 10. History of epilepsy. 11. Periocular skin lesions. 12. Anxiety with Geriatric Anxiety Scale score \> 12. 13. History of claustrophobia. 14. Participation in another clinical trial within the past 3 months involving medication or training that could affect the eyes. 15. Physical or mental conditions that may increase the risk of participation or interfere with study assessments (e.g., dementia). 16. Previous ocular electrical stimulation treatment or visual training study within the past 12 months. 17. Uncontrolled hypertension or diabetes. 18. Pregnant or breastfeeding. 19. History of craniotomy, burr hole surgery, head trauma, intracranial tumor, vascular malformation, or intracranial surgery.