I had my renewal this morning and I can cofirm all of the above plus discussions about past medical episodes and incidents (don't be fooled by thinking it's just a friendly chat). Explain any points on your application clearly and honestly no matter how trival it might sound to you. The eye examination was thorough to the say the least and if I spent any longer with the optometrist I would have become very concerned
The doctor also checked muscular movement, balance and stance. The Audiogram was also a right problem because of the sounds from the adjoining rooms, bugger ! That made it much harder but hey I passed nicely.
I saw one guy get called in by the same doctor a number of times and he didn't look too happy about it, not sure what the deal was there. Regardless you should just stay away from the tea and coffee for a couple of days before hand, get some decent sleep and maybe go to the gym in the days preceding your appointment.
Just be cool don't stress yourself out and cause problems for yourself especially in the blood pressure measurement