PURPOSE: Because stress can aggravate vascular dysregulation (VD) in primary open-angle glaucoma (POAG), stress reduction by eye yoga (EY) was studied if this predictive, preventive, and personalized medical (3PM) approach could help normalize intraocular pressure (IOP), retinal vessel dynamics, and visual fields (VF). PATIENTS AND METHODS: POAG patients were randomized to an EY ( RESULTS: After intervention, EY patients, but not controls, showed a 6.4% IOP reduction ( CONCLUSIONS AND 3PM RECOMMENDATIONS: Because EY reduces vasoconstriction and improves VF function in POAG, we propose the "eye ball retraction theory," whereby ocular muscle tension is induced by mental stress which is a contributing mechanism, or even the key mechanism, of POAG. Reducing stress by relaxation is therefore a remedy for it improves blood flow as the fundamental mechanism of vision recovery and restoration. VD reduction is therefore a valuable therapeutic target for glaucoma care and eye yoga home exercises are a safe and effective complementary 3PM method of POAG care. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13167-024-00389-x.