I really do get you are trying to say...and yes, I have been to see 'bad' opticians as well and switched to different place where I have been treated much better.
Yes, eye tests are yearly bother...something I could do without, but I do see them being beneficial to be worth it. The eye test and diabetic screening is not all about just what you are able or not to see...all the different tests are done to measure different things or possible changes within eye ball. Many health conditions can be detected from eye by just visual look into to the structure and with all the different measurements too....often those changes can show health change issues and can alert to them in our health before it is obvious in rest of the body, like a early warning system......so in that way, they are good to have done.
Or so I have been told...I don't personally have training for these things.
But, like with any medications etc..it is your body, if you don't drive and don't want to have/change your glasses...nobody can't force you for it.
I would not accept the attitude and treatment you have been getting from your optician and their receptionist. If they are just branch from a bigger optician business....I would send email to their head office and make complaint.
Some businesses make 'issue' that they do their diabetic screening and eye test over two different appointments...yes, they might tell you that, but if you put your foot down and say it is not suitable for you, no business who can't afford to loose potential customer, will refuse do it all in one go. Specsavers did try that on me...but I didn't agree...
If they are small independent business and you have other options locally to you....'vote' with your feet and don't bother with their 'services'. What ever you decide to do...if you do feel you don't get the service that is fair...don't be afraid to open your mouth and question why it is so...sometimes they need to be pointed the obvious or taken down from their high horse before they change their attitudes.
I would also recommend when you see the optician...just make conversation about all the different tests that are done to you and ask what they are for, what they are measuring, what they can see from those tests etc. It is your body they are testing, just like any other tests are done in doctor's...you are entitled to know answers what is done to you, why and the results for them.
Not only that....by making all those questions...if not just for sake of conversation, you might just make that opticians day that little bit more interesting...maybe you turn out to be that somebody who is showing interest for their work and knowledge for it...giving the change them to 'show it off' too...which again might result bit better attention for the details from their behalf....you will benefit and he does feel better..win win...
BTW...;Yes, just like any business, they will try to sell you things, even if you don't really need or want 'stuff'..that's where they make their money from. I always make clear to my optician, that if my glasses are adequate for my needs, that will do for me (or what ever my choice is!), they can do their recommendations but ultimately I make my own choices. I do drive, so that will be limitation, as if the prescription has to change then there is not much to argue about.