I really  appreciate all the replies  so far.    I dont know how it
happened.  She seemed fine yesterday evening, but she may have caught
a paw  in a play fight  with my other cat.  Hard to say.     But that
eye is sometimes a little vulnerable to becomomg  mucky,  usually
resolved simply by a with with some clean wet tissue.   Never anything
like this though before.

She messed her carrying cage at the vets  she was so stressed,  then
after a dye  and light test we were able to come home.  During the
day  she ate well, played several times  for up to 5  to 10 minutes
and groomed  normally., and it seemed the eye got gradually a bit less
closed, sometimes around  half  open.  Then early  evening I used  the
first application of fulcithalmic and that made her whinge and paw  at
herself  again a;beit only  for a  second .  But probably because an
initial stinging is to be expected (I looked at some internet notes
about the drug)  .   Since  abouit 6pm  she hasnt been pawing at it
(now 9.35 pm  UK time)  but  she is keeping the eye fairly  closed.

I have seen lots of stuff on the net   about these problems  and how
they can date back to viruses caught when kittens  etc etc.

I have the E  collar  ready, and will keep it by  the bed.  Hopefulyl
I wont need to put it on her.

I hope  there isnt any distressing pain for her in the night being
as  the vets  painkiller injection was at 9 am .   One because I
wouldnt want her to suffer, and (2)  because  the vet charges  120
pounds  to come out in the night  and in my opinion, oral painkillers
should have been prescribed this morning for this  8mm abrasion/ulcer
with some conjunctivitis  with the cause unknown.   It would be
outt=rageous to have to pay 120  in these  circumstances.

The vet probably has seen hundreds of cases  and probably I am getting
over worried  about a everyday case .

I will keep you posted :)

Thanks  again.