A 39-year-old man was admitted with a sudden visual loss in the left eye. Visual acuities were 10/10 on the right and 1/10 on the left. Fundus examination did not show any abnormalities. Visual acuity improved to 10/10 and visual field defect regressed in the following 2 weeks. Three years later, the patient returned with acute visual loss in the right eye. Visual acuities were 2/10 on the right and 10/10 on the left. Right optic disc had blurred margins with mild oedema. The tests revealed methylenetetrahydrofolate reductase A1298C mutation with positive lupus anticoagulant and hyperhomocysteinaemia. Enoxaparin was initialised with vitamin B12 supplementation. Complete visual recovery occurred in the following 3 weeks in both eyes. Thrombophilic screening seems to be important in the treatment and prevention of an attack in the second eye of patients with non-arteritic anterior ischaemic optic neuropathy.