I kind of got caught out by this by attending A&E with severe uveitis. It turns out there are no eye specialist departments or referrals from A&E so it all needs to happen through private opticians. Personally did not realise opticians could do prescriptions beyond prescribing specific lens types.

My eye was so swollen that it ultimately needed atropine to unstick my pupil from the lens, in addition to steroids to fix the underlying condition.