The local anaesthetic drops, which you'll probably get, don't affect your vision at all. The pupil dilation ones make it near-impossible to cycle for about 4 hours. I did it, being a bit too far from home to walk, and could barely stay on the psyclepath and road although I know it very well. Also, bright sunlight hurts.
Be warned: you can't even read the time on your watch, let alone bus timetables and things, if your pupils are dilated.