Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
1
Is any of this happening now?
Call 911
Seek emergency care for:
Sudden severe vision loss, especially if it occurs within minutes
Vision loss in both eyes
Vision changes with weakness, numbness, difficulty speaking or severe imbalance
Severe eye pain with a red eye, headache, nausea or vomiting
New vision loss after a significant eye or head injury
These symptoms do not always mean optic neuritis.
They can occur with stroke, retinal problems, dangerously raised eye pressure and other conditions needing immediate assessment.
Other emergency signs, for anyone
Someone who is struggling to breathe, gasping, choking, or cannot get words out
Someone who has chest pain, tightness or pressure lasting more than a few minutes
Someone who has sudden weakness or drooping on one side of the face or body, slurred speech, or sudden confusion
Someone who is unconscious, or cannot be woken
Someone who is bleeding heavily and it will not stop with firm pressure
Someone who has had a seizure that will not stop, or does not wake up afterwards
Someone who has lips or skin that look pale, blue, grey or blotchy
Someone who you believe has taken an overdose or swallowed something poisonous
2
Is any of this happening?
Be seen today
Arrange urgent, same-day medical assessment for any new or unexplained loss of vision, pain with eye movement accompanied by visual change, or colours suddenly appearing faded in one eye.
Do not wait for a routine eye test if vision is actively worsening.
Contact your usual eye or neurological team promptly if previously stable vision worsens, symptoms return in either eye, or new neurological symptoms develop.
3
Does any of this apply?
Book an appointment
Routine follow-up is appropriate for stable recovery, test review and discussion of long-term risk.
Every sign above is quoted from the sofidex article on Optic neuritis. If you are not sure, err upward — it is always reasonable to be checked.