A big thanks to all your comments have been very helpful.Not sure if I will do a practice run as I don’t think they do them at my opticians which is a specsavers but not one that does DVLA tests.
DVLA driving test: A big thanks to all your... - Glaucoma UK
DVLA driving test
I failed the DVLA test at one branch of Specsavers due to it not being done correctly, I then took the same test at two other branches of Specsavers one was DVLA licensed one wasn't both results were similar and passed easily I appealed to DVLA and after emailing the DVLA glaucoma advice service I got my licence back and a week later an apology from the DVLA effectively saying that the first test was incorrectly carried out. SSo I would definitely have a trial test at any Specsavers that has the same equipment whether they are DVLA licensed and if you're not happy do another one, it's worth the effort of travelling mine charged £22 per test.
I did a practice run this morning at a cost of £35 at the branch where I will take the test . It was money well spent and familiarised me with the equipment . I was also able to talk to the staff and find out when the quietest times usually are .