Symptom

Sudden vision loss

Medical emergency: seek care now

Medical reviewer Mr Mohamed Mohyudin· Last recorded site review

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Seek emergency care now if you have

  • Sudden loss of vision in one or both eyes
  • A dark shadow or curtain spreading across your vision
  • Sudden vision loss with weakness, numbness or slurred speech
  • Sudden painful vision loss with a red eye, halos or nausea

Possible causes

Sudden vision loss has several serious causes. Seek emergency care first; these are conditions to understand afterwards.

Retinal detachmentFlashes, floaters and a shadow over vision; an emergency.Retinal artery occlusionSudden painless severe vision loss from a blocked artery — an emergency.Retinal vein occlusionBlocked vein at the back of the eye causing sudden blurring or a dark patch.Optic neuritisSudden blurred or lost vision in one eye, often with pain on eye movement.Giant cell arteritisHeadache, scalp tenderness and jaw pain with vision loss in people over 50 — emergency.GlaucomaAcute glaucoma causes sudden painful loss with halos and nausea.Age-related macular degenerationWet macular degeneration can cause sudden central vision change.Diabetic retinopathyBleeding in the eye can cause sudden loss in people with diabetes.Ocular migraine (visual aura)Migraine aura causes temporary disturbance that recovers, but new loss must still be checked.

Frequently asked questions

Is sudden vision loss an emergency?

Yes. Any sudden loss of vision, in one or both eyes and whether painful or painless, is a medical emergency that needs immediate care.

What should I do if I suddenly lose vision?

Seek emergency eye care immediately rather than waiting to see if it improves, as prompt treatment offers the best chance of protecting sight.

Can sudden vision loss come back?

Some causes, such as migraine aura, recover on their own, but you cannot know the cause without assessment, so sudden vision loss must always be treated as an emergency.

Your next step

Take this to your appointment

Write down what has changed, when it started, your current medicines and the questions you want answered. Take these to your eye-care appointment.

Patient resourcesFind care where you live →

Sudden loss of sight, severe eye pain or a dark curtain across vision needs immediate assessment. Do not wait to complete a worksheet.

Sources for this information

These references support the information on this page. Follow the linked source for its full context.