Camilla - I don't know what kind of vision issues he has, or what kind of glasses - but if he has 'normal' glasses and his issues is 'short-sightedness' or something like that - then that is not what we are talking about.
AFAIK only an OT will test for visual discrimination / visual perception issues. An OT was certainly the person who told me DS1 had these issues.
Glasses won't help with visual discrimination problems.
And again there is quite a high chance he has eye tracking issues. Opticians don't test for this, so it's very possible he hasn't been tested for it. And again glasses don't help with it.
RRT is Retained Reflex Therapy, and is very good. However therapies like this take a while to get your head round and are not normally the place people start.
When you're ready for alternative therapies like RRT, these are the kind of places me and Debbie and others on the SN board have found have really helped our children:
Tinsley House
INPP
Hemispheres
Sound Learning Centre
All of these places are excellent - particularly Tinsley House. But don't go to them till you've got your head a bit more round his problems, and are prepared to do therapy with him every day for a year.......
An OT and a behaviour optometrist are a good place to start. But that's all they are - a starting place. If your DS is as bad as he sounds, it'll take you a couple of years and quite a few different therapies to get him to where he needs to be.
It can be done. But it takes a lot of time, patience and money. And most of all determination and utter faith. You have to believe he's capable of far more and that you will move heaven and earth to help him.
Once you've got your head there, the rest's easy :)