Here is a little story sent by one of my readers, who, for reasons which will become obvious wishes to remain anonymous.
Dr X is an anaesthetist. It is the end of a long day. Dr X has been on an eye surgery list, putting in peri bulbar or sub tenon blocks, as well as the odd general anaesthetic.
He quickly and efficiently puts a peri bulbar block into the last patient. As is often the case the patient finds this a brief, but unpleasant experience, but tolerates the procedure with quiet stoicism. Dr X finishes and asks if the patient is OK.
"Yes" replies the patient, "but they are operating on this eye" he says, pointing to the other side.
" Oh yes" thinks Dr X. "The eye with the dilated pupil, and the big arrow over it"