I find that the pre liquid they use really upsets my eyes and stings like a wasp.
I have annual tests for Glaucoma as my Mum has it. The drops you get that dilate your eyes are harsh. I cycle up to the hospital (30km each way) and have to wear industrial strength shades coming home as it's so bright - even on a dull day .
I've had annual tests for glaucoma for ten years now, but nobody's ever given me drops. Now I feel that I'm missing out.
It depends on the technique used to measure intraocular pressure.
In one, they just blast a puff of air at the unanaesthetised eye and record how it 'bounces'. This is quick, cheap and slightly unreliable.
The other technique requires an instrument to be applied onto the cornea. This requires the use of local anaesthetic drops, which smart and sting.
When the retina is photographed, or examined in detail, drops are used to dilate the pupil. This also paralyses the focusing mechanism.
It's really best to get a lift back from the eye clinic after this. I took the bus and was OK.