DS is 11 and in Year 7. When DS was 7 he said that letters move around the page, dance, spin, and hide. He had an assessment for dyslexia and the outcome was that he didn't hit enough markers for a diagnosis but those that he did hit he hit very strongly. He was subsequently diagnosed with visual stress and wears dark glasses and uses yellow overlays/yellow paper which do help but doesn't completely solve the problem.
I have not had any anxieties over his academic abilities as he did well in school and was predicted level 7s in every subject at KS 3. For various reasons he has recently been deregistered from school and I have taken over his education to discover that he cannot spell. How he did so well in the national and school tests I have no idea as he really can't spell very well at all. He also has trouble reading unfamiliar words. This isn't obvious as his vocabulary is very good so he doesn't often come up against unfamiliar words but obviously this is going to increase as he continues with his education. What he says is often an anagram of what is on the page iyswim.
I'm assuming he should now be reassessed and I was wondering if it is common for a child not to be diagnosed and then go on to be diagnosed at a later assessment? TIA