Quick answer
What could sudden vision loss mean?
Sudden loss of vision in one or both eyes is an emergency. Call 999 if it occurs with facial droop, arm weakness, speech difficulty, severe headache, confusion or dizziness. Otherwise seek immediate eye emergency or A&E assessment; do not wait for a routine optician appointment.
Describe the change
Note whether one or both eyes are affected, whether vision is dark, blurred or missing in an area, and whether there is pain, redness, flashes, floaters or neurological symptoms.
Possible causes
Important causes include retinal artery blockage, retinal detachment, stroke or TIA, optic nerve inflammation and acute glaucoma. Migraine aura can affect vision, but a first or unusual episode still needs assessment.
Do not delay
Some treatments are time-critical. Bring glasses, contact-lens details and a medicine list, and avoid eating if emergency surgery might be needed unless clinicians advise otherwise.
Common questions about sudden vision loss
- What if my sight returned after a few minutes?
- Temporary loss still needs urgent assessment because it can be caused by reduced blood flow to the eye or brain.
- Are flashes and floaters always an emergency?
- New or suddenly increasing flashes and floaters, especially with a shadow or reduced vision, need same-day eye assessment.
- Should I see an optician or A&E?
- For sudden vision loss, use an emergency eye service or A&E. Call 999 when stroke symptoms or severe illness accompany it.