The literature describes previous cases of nonarteritic anterior ischaemic optic neuropathy (NAION) following rapid rises in intraocular pressure (IOP) leading to reduced optic nerve head perfusion and disruption. This is commonly following ophthalmic procedures, acute glaucoma or steroid eye drops. The authors present the distinct case of a left NAION on the background for treatment of herpes zoster ophthalmicus (HZO). A 61-year-old woman sought consultation for a left optic neuropathy and development of skin lesions on the tip and side of her nose and left forehead in keeping with HZO. After a prescription of Valacyclovir 1g PO TID, she presented two days later with a left anterior uveitis and an IOP of 18 for which she was started on Prednisolone acetate 1% eye drops. Two weeks later, she presented acutely with left eye pain and worsening vision and found to have an IOP of 52. Prednisolone was discontinued and she was administered systemic and topical IOP lowering drugs. Examination the following day revealed an IOP of 16, a new relative afferent pupillary defect (RAPD), and optic disc oedema. After stopping the IOP lowering drugs, neuro-ophthalmology input demonstrated 20/20 OD, 20/100 OS, a left RAPD, left optic disc oedema, and a left inferior altitudinal visual defect. The differential diagnoses at this time point was a left NAION due to either HZO or the recent IOP spike. An anterior chamber paracentesis for varicella zoster virus (VZV) detected no virus and an MRI contrast of the brain and orbits came back normal. At three months follow-up, the left optic disc oedema had resolved, but the visual field defect persisted. The authors concluded her diagnosis of NAION as secondary to the IOP spike given the temporal relationship between the two, the symptom onset, and negative results for the VZV. The authors stress the importance of closely monitoring patients on topical steroids for rare and irreversible complications including but not limited to NAION.