Optimal Non-invasive Brain Stimulation for Peripheral Vision

Inclusion Criteria: 1. Age range from 18 to 80 years; 2. Diagnosis of primary open angle or normal tension glaucoma with relative scotoma in both eyes; 3. A relative scotoma defined as a Humphrey Field Analyser (HFA) threshold perimetry loss (mean deviation of ≤-6dB) within the central 30° of the visual field for at least one eye; 4. Best-corrected distance visual acuity of 6/12 or better (equivalent to 0.3 logMAR acuity or better to confirm that participant's central vision is preserved); 5. Stable vision and visual field loss for at least 3 months; 6. With a cognitive functional score of 22 or above in the Montreal Cognitive Assessment - Hong Kong version (HK-MoCA) (to confirm participant's intact cognitive function). Exclusion Criteria: 1. Ocular diseases other than glaucoma (e.g. age-related macular degeneration, diabetic retinopathy, moderate to severe cataract) or severe hearing impairment (to ensure that participant can hear the instructions clearly during assessments and training); 2. Severe medical problems (e.g. stroke, Parkinson's disease) or self-reported neurological (e.g. brain surgery, brain tumor, peripheral neuropathy), or cognitive disorders (e.g. diagnosed dementia or cognitive impairment); 3. Self-reported vestibular or cerebellar dysfunction, history of vertigo; 4. Using any medications for any neurological conditions or psychiatric drugs (e.g. sedative, hypnotic) that might interfere with motor control; 5. Contraindications for non-invasive brain stimulation.