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
If same-day eye care is unavailable, go to an emergency department.
Sudden major vision loss or a serious eye injury requires immediate emergency care.
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 a same-day assessment by an optometrist or ophthalmologist if you develop:
A sudden first episode or sudden increase in floaters
Floaters with new flashes of light
A dark curtain, shadow, or veil across your vision
Missing, blurred, or reduced vision
New floaters after an eye injury or eye operation
Longstanding, unchanged floaters without flashes or vision loss are less likely to be urgent, but you can still discuss them at a regular eye examination.
Seek prompt advice if either occurs, particularly with light sensitivity or reduced vision.
3
Does any of this apply?
Book an appointment
Book a routine appointment if your floaters appeared gradually, are becoming more noticeable, or interfere with reading, driving, or work.
The article also says
An ophthalmologist is a doctor who specialises in eye conditions and surgery.
Eye pain or redness is not typical of simple age-related floaters.
Every sign above is quoted from the sofidex article on Eye floaters. If you are not sure, err upward — it is always reasonable to be checked.