hi im new please help

Hi I'm new here and I need some advice.


My son is 3yo and is being assessed for autism. Last wk we had another dreaded optician appointment. He hates people coming near him especially near his face. Also he doesn't sit on my knee for long and if I try to hold him he struggles. We got a vision test done with one eye covered but that was all. After that he went into melt down! He gets the eye drops to check his prescription hasn't changed but the only way to check that his glasses are actually working for him is a vision test and it has to be done first because the eye drops make their sight blurred. 


So we're going back for another appointment tmro which I'm sure he won't appreciate. 


He's v difficult to control and work with. He also has speech and understanding delays which makes him ( and me in public situations ) very frustrated. We are still learning! People look at me like I'm an awful mum because I can't always work with him esp in public places in fact I have a neighbour who complained about his crying.


Anyway can anyone please give me some advice on how to help my son and me in such situations so we can have this eye examination done? 


Many thanks xx