The goal of this clinical trial is to use different tES techniques to constantly stimulate the cerebellum in older glaucoma patients. The main questions aim to answer :
1. If the different types of tES targeting the cerebellum can modulate glaucoma patients' balance function and visual-cognitive function? 2. Which tES techniques among the two types can benefit most?
Participants will be required to receive the stimulation 15 times (3 sessions, 5 continuous days/session, 1-week interval between each session), and complete the balance and visual-cognitive function outcome measurements before and after each session.
Age over 55 years old;
Diagnosis of primary open-angle or normal-tension glaucoma with relative scotoma in both eyes;
Humphrey Field Analyzer visual field loss (mean deviation of ≤- 6 dB) using the 24-2 testing protocol for both eyes;
Best-corrected distance visual acuity of 6/12 (equivalent to 0.3 logMAR) or better;
Have musculoskeletal disorders or neurological diseases that can affect the balance or nervous system.
Ocular diseases other than glaucoma (e.g., age-related macular degeneration, diabetic retinopathy, moderate to severe cataract) or severe hearing impairment (to ensure that participants can hear the instructions clearly during assessments and training)
Have any contraindications for tES