Eye care

One in three optometrists say they have seen patients in the last month who continue to drive with vision below the legal standard, their association said.

Motorists must read a number plate from 20m (65ft) in the practical driving test, but there is no follow-up check.

The Department for Transport said changes to eyesight should be reported by motorists to the DVLA.

"All drivers are required by law to make sure their eyesight is good enough to drive," a spokeswoman said.

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."