I had virtually settled on a date for laser eye surgery when the train driving job came along and in a matter of a few short weeks, I was into assessments and interviews (for GTR). Consequently I never followed through with the eye surgery as I had always been led to believe that it was not accepted.
Fast forward to the day of the medical (at BUPA, near Kings Cross) and although I wear glasses, it is only a small correction I need. In fact, I passed the eye test before I even got to put my glasses on! This was all conducted by a 'nurse', the final aspect of the medical being with an actual doctor.
Whilst I was in with the doctor he just checked some previous/existing conditions; I'd been in the army for 24 years and hadn't quite been totally unscathed! Reconstruction surgery on my shoulder, two damaged discs in my lower back and worn out knees were all checked for RoM (range of movement) and reflexes etc.
The doctor was about to end the consultation with "congratulations, no problems" when I asked what was the score with laser eye surgery. No one had actually looked into my eyes which is evidently when they can see if you have had any procedures. The doctor asked why I was asking as I was the second person that day who had asked. He stated that as far as he was aware there was no restriction regarding laser eye surgery, so long as your eyes met the required standard and that it was more than a month previous (same for any surgery). He then checked 'the rules' and confirmed that what he had just told me was indeed correct.
It was a bit frustrating for me as I could have gone ahead and had my eyes lasered but it won't be quite that easy now (month of work to meet the requirements). As it transpired, there were two people on my course who had had their eyes lasered in the past.
BTW, bifocal glasses are permitted as a driver, varifocal's aren't.
In summary, it won't be a problem for you.