Taking this even further, I am wondering if the clinically significant differences between expected performance and actual performance on the WIAT could be at least partially explained by vision...

Our results show a word reading score 36pts HIGHER than predicted by VIQ (perhaps ceiling related?? Word Reading was a perfect 160 on WIAT) and math reasoning score 26pts LOWER than predicted by PIQ.

I think I am generally looking back saying, "Oh!" now that makes sense to me. Back then it was more these are unusual scores but we don't know why.