To report a case of severe eye pain developing during dialysis. A case report was performed. A 41-year-old man with uncontrolled type 2 diabetes and end-stage nephropathy developed severe pain in the left eye during hemodialysis. A decline in vision in both eyes was reported over the preceding year, with blindness in the left eye for 6 months. The best-corrected visual acuity was 20/150 OD and light perception OS. The intraocular pressure was 14 mm Hg and 59 mm Hg, respectively. An examination found disc neovascularization with a “volcanic eruption” of vitreous hemorrhage from the optic nerve in the right eye and significant corneal edema and iris neovascularization with no posterior view in the left eye. The patient required urgent cyclophotocoagulation for neovascular glaucoma (NVG) in the left eye, bilateral antivascular endothelial growth factor injections, and panretinal photocoagulation in the right eye for proliferative diabetic retinopathy. Worsening eye pain during hemodialysis in a patient with NVG indicates severely limited outflow capacity and requires immediate intervention.© The Author(s) 2024.