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What to do if…
you have sudden loss of vision in one eye or a curtain-like shadow

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy USA guide

Short answer

If you have sudden one-eye vision loss, a curtain-like shadow, or sudden trouble seeing with possible stroke signs, get urgent help now. Call 911 if you have stroke warning signs, cannot travel safely, or cannot get urgent eye care right away; otherwise contact an ophthalmologist or go to the emergency room right away.

Do not do these things

  • Do not “wait and see,” even if it is painless or seems to come and go.
  • Do not drive yourself if your vision is affected, you feel unwell, or stroke is possible.
  • Do not rub, press, or put pressure on the eye.
  • Do not use leftover prescription eye drops or medication unless a clinician tells you to.
  • Do not put contact lenses back in; keep them out.
  • Do not assume it is “just eye strain” or “just a migraine” if this is new or one-sided, especially with a curtain-like shadow.

What to do now

  1. Check for stroke warning signs and act immediately.
    If you have face drooping, arm weakness or numbness, speech trouble, confusion, sudden trouble walking or balance problems, or a sudden severe headache with no known cause, call 911 and say: “Sudden trouble seeing in one eye” or “curtain-like shadow in one eye.”
  2. If there are no stroke signs, still treat this as urgent.
    Call an ophthalmologist or eye emergency service if this gets you seen immediately. If not, go to the emergency room now.
  3. Do not travel alone if your vision is affected.
    Ask someone to take you, use a ride service, or call 911 if you cannot get there safely. If stroke signs are present, call 911 instead of using a ride service.
  4. If you are alone, make the next few minutes safer.
    Sit down away from stairs, unlock your door if emergency help may need to enter, keep your phone with you, and call someone nearby to come over if that does not delay urgent care.
  5. Record the timing.
    Write down when the vision change started, when you were last seeing normally, whether it is improving or worsening, and whether it has happened before.
  6. Make a short symptom note for EMS, the emergency room, or the eye doctor.
    Include which eye is affected, whether the curtain or shadow is spreading or fixed, whether you have flashes of light or sudden new floaters, whether there is eye pain or redness, and whether there was recent eye injury or eye surgery.
  7. Bring only what is easy to grab.
    Take your medication list or medication bottles, allergies, ID, insurance information if available, glasses, contact lens case, and the name of someone staff can call.

What can wait

  • You do not need to figure out the cause before getting help.
  • You do not need to keep testing your vision, search symptoms online, or try home remedies right now.
  • You do not need to decide about insurance forms, bills, transport home, or follow-up scheduling right now; first get urgent evaluation.

Important reassurance

This is a scary symptom, and it makes sense to feel alarmed. Some causes of sudden one-eye vision change are time-sensitive, so getting urgent evaluation quickly is the safest choice even if vision partly returns.

Scope note

These are first steps only, focused on rapid and safe access to urgent care. Later decisions about tests, treatment, or follow-up may need help from an emergency clinician, ophthalmologist, neurologist, or another specialist.

Important note

This guide is general information, not medical advice, a diagnosis, or a substitute for emergency or professional care. Sudden trouble seeing in one eye or a curtain-like shadow can be an emergency; if you are unsure, call 911 or seek emergency care.

Additional Resources

Closely connected guides that may be useful during the same situation or its immediate aftermath.

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

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