New glasses and prism - think prescription is wrong?

[Blooter]

I have a mild vertical eye muscle imbalance. I see things with my right eye lower down than my left. I've been prescribed glasses with a small prism in my right eye (base up 0.5).

I've just picked up my glasses and am confused because the right lens moves images down. Shouldn't I have a prism that moves the right eye image up rather than down? So that my left eye and right eye see things at the same level?

My main issue is eye strain and headaches and I'm worried that if the prism is wrong this is only going to get worse. I did ask the assistant who fitted my glasses but he mumbled some stuff that didn't make sense and I got the impression he didn't know. I'm kicking myself now for just coming home with them and not asking for more clarification.

Anyone?

Take them back and explain, it's quite possible they've got it wrong, it happens a lot.

Thanks. I was hoping there might be an optician on mumsnet who could tell me if I should have an up or down prism as unless I make another optician appointment I don't think the assistants will have any answers for me.

The assistants will get the optician to check, seriously, just take them back.

Dispensing optician here...

I'm struggling to understand why they have given you prism in the Right eye only. It's more common to put half the amount of prism in both eyes, this usually brings a better balance. In any case, if you are unhappy/concerned about your spex please don't struggle on, call them and ask to book a recheck. X

Yeah just take them back. I had an issue with my newest glasses - wasn’t obvious in the shop but when driving I couldn’t see! Turned out the optician had mistakenly put my astigmatism as 125 instead of 25 on one eye.

Easily fixed. They booked me in for an appointment a couple of days later when they checked the prescription against the glasses and then a quick check to make sure my eyes hadn’t suddenly got worse.

Thanks. The thing is, the prism is quite small so my vision doesn't change significantly when wearing my glasses so there's not really anything I can put my finger on to complain about. I can see fine with them. My problems are eyestrain and headaches and it takes a couple of weeks to know the impact of new glasses.

It's hard to question an optician and suggest they've got it wrong when I don't really understand how prisms work and why they are making the image in my right eye even lower when it is already too low.

What I would like to know is if I see things lower with my right eye should the prism be base down so that the image is raised? I don't understand why they have made the prism base up, but when I asked this when I got my prescription I didn't understand the explanation. So I'm feeling unsure whether I just don't understand it or if the optician doesn't understand it and has made a mistake!

Hoping that an optician might be on here this morning?!