hi,
i live in portchester (between portsmouth and southampton) and have actually had some luck with finding a good vet for pascal, since being a baby he has had 3 different vets - a checkup vet who doesnt specialise in reptiles but knows a good bit, a vet abit further away for when something goes wrong, and then a VERY highly recommended specialist just in case
my "if something goes wrong vet" is called Downlands Vets, and is the one in emsworth, it has two reptile specialists who are used to chameleons - david vawer and ben trimmer. these guys are really friendly, know their stuff and from my experience get it right first time, they fixed pascals eye problem straight away with eye drops, told me how to use them, etc, showed me a few things about pascal and invited me back just to make sure the treatment was working. the staff are lovely, and pascals treatment only cost me £40
my emergency contact is a well recommended "zoological vet" who does all the advanced surgery on rare exotics etc, has a weekly schedule so booking him could be a bit of a pain, but he was very friendly on the phone and is another one that isnt going to bullshit money out of you, he's called John Chitty, lost his phone number since getting a new mobile but what i did was email him with details of the problem, leave him my number and he actually rang me back - here is his website
http://www.jcexoticpetconsultancy.co.uk/page9.html
and the website for the vets in emsworth
http://www.downlandvets.co.uk/emsworth-staff.html
i hope this has helped and that these guys are as helpful to you as they were to me