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
Call emergency services for sudden vision loss accompanied by facial weakness, arm weakness, trouble speaking, severe imbalance, or a sudden severe headache.
These can be signs of a neurological emergency rather than presbyopia.
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
Seek prompt medical assessment if vision changes rapidly, affects only one eye, or comes with new double vision.
These patterns are not typical of ordinary presbyopia.
Seek urgent, same-day eye care for:
New flashes of light, many floaters, or a curtain-like shadow
A painful red eye, especially with nausea or blurred vision
Sudden marked loss of vision
Eye injury or chemical exposure
3
Does any of this apply?
Book an appointment
Arrange a routine eye examination if close vision is gradually becoming blurred, you need brighter light, or reading causes repeated eyestrain or headaches.
Routine review is also appropriate if your current glasses or contact lenses no longer meet your needs.
Every sign above is quoted from the sofidex article on Presbyopia. If you are not sure, err upward — it is always reasonable to be checked.