Wow. Evan is (as far as I know) also red/green colour blind.
All very interesting. He has an appointment with a behavioural optometrist next wednesday so I will ask him then. There is a centre here in cairns that specialises in Irlen also, so hopefully if we need to go down that path it will be easily accessible.

What sort of signs made you look into Irlen? Evan can read ok. But his comprehension is the problem.