One of the most interesting bits of research I ran across about challenges and inteligence is that intelligence is a better predictor of vision problems than parental vision problems.
I have pretty severe astigmatism in one eye, and totally missed that DS had even worse than I did until it came up at his physical for kindergarten. Neither of us is good at procedural memory for things like tying shoes. In addition to whatever contribution vision made, he very much operated on his own plan at five and would have had completely meaningless resukts testing at that age. At almost seven with some correction for his vision his testing was ok, but heavily skewed on vision elements on the Stanford Binet.
A ten second screening at home of covering each eye and trying to read would've told us there was an issue. Normal vision is whatever an individual experiences and they operated under the assumption that everyone sees the same until told differently. Headaches can also be a huge red flag.
