Sudden curtain-like loss of vision in one eye needs same-day stroke emergency assessment, even if it resolves within minutes
A sudden dark curtain over one eye can mean retinal blood-vessel obstruction; longer loss of blood supply leaves less retina salvageable. It can also signal ischemia and risk of stroke in the next few days. In a study of minor stroke and transient ischemic attacks, same-day assessment and treatment reduced 90-day recurrent stroke from 10.3% to 2.1%. Go to a stroke-capable emergency department that day rather than waiting for tomorrow's eye clinic.
What it takes
The immediate decision costs nothing. Emergency and vascular assessment can take half a day to a day.
What you may gain
The American Heart Association's 2021 statement calls acute central retinal artery occlusion an emergency requiring rapid recognition and triage. The longer retinal ischemia continues, the less tissue remains salvageable. Oxford's EXPRESS study examined minor stroke and transient ischemic attack, where symptoms resolve. After the service switched to same-day assessment and treatment, 90-day recurrent stroke fell from 10.3% (32/310) to 2.1% (6/281).
Context & considerations
Grade B because EXPRESS compared periods before and after a service change rather than randomized groups; other changes cannot be separated. Vision that returns after minutes is easily dismissed as tiredness or low glucose, but transient retinal ischemia can precede stroke during the following high-risk days. Painless one-eye vision loss without redness or tearing especially deserves attention. Go directly to emergency care at a stroke-capable hospital.
Research & references
Mac Grory B, Schrag M, Biousse V, et al. (2021). Management of Central Retinal Artery Occlusion: A Scientific Statement From the American Heart Association. Stroke, 52(6), e282-e294. https://doi.org/10.1161/STR.0000000000000366; Rothwell PM, Giles MF, Chandratheva A, et al. (2007). Effect of urgent treatment of transient ischaemic attack and minor stroke on early recurrent stroke (EXPRESS study): a prospective population-based sequential comparison. Lancet, 370(9596), 1432-1442. https://doi.org/10.1016/S0140-6736(07)61448-2