Sue, I can understand your apprehension about the operation but please don't worry about pain. I had the same operation a few years ago and can honestly say that there was no pain.
They put 2 different types of drops in your eye one to dilate the pupil and the other is a local anaesthetic, you do have an injection just before they start surgery but it is uncomfortable rather than painful.

Please try not to worry about pain, even if you have a low pain threshold it really isn't painful and the end result is wonderful

Kate x