Andrew Hogan of Optometry Australia sees a lot of children in his practice in Hobart, often when parents or teachers notice one of those symptoms.
"Kids won't complain about blurry vision," he told Helen Shield on ABC Radio Hobart.
"Kids who aren't paying attention [in class], sometimes it's simply because they can't see and they don't realise that everyone else can see, because they've got nothing to compare it to."