I have had two in two weeks. I am the diabetic eye test Tsar. Take shades, afterwards everything is really bright as your pupils are open for ages after by the eye drops.
The first test I had was a simple screening that lasted about half an hour, a quick eye test then eye drops then a short wait while they then take the pictures of the back of your eye. The drops didn't hurt me at all but some people find that they sting a bit.
I was told as a result of that screening that I had diabetic maculopathy and need a more indepth screening.
The second was one was a bit more gruelling and uncomfortable, more drops and other coloured dyes, then another photograph session then another indepth exam with lots of bright lights and looking looking looking.
It seemed as if my pupils were open even more the second time so afterwards the brightness was a bit intense and I had a bit of a kip.
I was told on the day that even though there was damage the work I had already done in the 2 months I have been diagnosed had been good and I didn't need any treatment at the moment. They said I may have stopped it developing further and my eyes will probably heal and be ok. Good news for an artist like me.
It was all a bit of a worry at first but none of it was too awful just a bit uncomfortable.
Good luck I hope it all goes OK . Tell us how you get on.