{Reference Type}: Case Reports {Title}: Non-arteritic anterior ischaemic optic neuropathy and obstructive sleep apnoea. {Author}: Madan S;Sethi M;Bajpai V;Garg R; {Journal}: Natl Med J India {Volume}: 36 {Issue}: 6 {Year}: 2023 Nov-Dec {Factor}: 0.559 {DOI}: 10.25259/NMJI_982_20 {Abstract}: Anterior ischaemic optic neuropathies (AIONs) are a common cause of permanent visual loss in the elderly population. The non-arteritic subtype has been intensively studied. While systemic associations such as hypertension and diabetes mellitus are commonly recognized and treated, others such as obstructive sleep apnoea (OSA) are largely overlooked in daily practice. A 60-year-old man who gave no history of any systemic illness presented to us 1 week following an uneventful cataract surgery with posterior chamber intraocular lens implantation in his right eye. The surgery was performed elsewhere by an eye-healthcare professional where the patient presented primarily with a history of progressively worsening diminution of vision in the same eye for 5 days and was diagnosed with a senile cataract. The postoperative visual gain was unsatisfactory; hence he sought another opinion. A diagnosis of non-arteritic AION (NAION) was established. Systemic evaluation revealed elevated diastolic blood pressure, dyslipidaemia and severe OSA. Prompt treatment with systemic steroids and simultaneous management of the accompanying systemic morbid conditions saved some useful vision in the affected eye. This also prevented involvement of the fellow unaffected eye. A comprehensive ocular examination with emphasis on systemic evaluation of the patient for coexisting illness is imperative before proceeding with any medical or surgical intervention. OSA is a definitive risk factor for the development of NAION, though it remains underdiagnosed and untreated. Cataract surgery has been shown to worsen underlying NAION. Systemic stabilization averts potentially blinding sequel in the unaffected eye of these patients.