Reading letters off a wall chart is far from the best way of predicting someone's safety on the road and one day the simple driver's licence eyesight test could become a thing of the past.
A study is currently underway focusing on the vision, memory, reaction times and driving skills of 600 drivers in Brisbane and Canberra in an attempt to find better ways of assessing the safety of older drivers.
The subjects have undergone vision, cognitive and physical testing and early indications suggest assessing motion sensitivity, colour change reaction time and postural sway would be better ways of predicting driver safety.
Queensland University of Technology's Professor Joanne Wood, from the school of optometry and vision science, revealed some of the preliminary findings at a public seminar on Friday into age-related eye diseases and the impact on driving performance and safety.
She said it suggested driver licensing should be based on performance not age.
"It makes sense, if we think of motion sensitivity things in the driving environment are moving all the time," she said.
"The visibility of things isn't as clear as those high contrast letter charts seem to suggest."
Professor Wood said the ability to respond quickly to a number of choices and having the strength to balance well were also good indicators of driver safety.
"Obviously we've got a lot more data to collect and analyse so we're reserving judgment at this time but the results so far seem pretty exciting and intuitive," she said.
But it may be a while before we can expect to see different eye tests when we go to renew our driver's licence, with the investigators wanting to ensure the results are repeated and the best replacement tests can be developed before making recommendations to authorities.
"The whole issue of driving is so emotive and so challenging," Professor Wood said.
"What we're really striving to do is find objective tests where they can say 'this person looks to be unsafe'.
"It's very difficult to say to someone of any age 'you're not a very good driver and it's even worse to try and take their licence away.
"GPs have a hard time."
Professor Wood said so far the results suggested the tests were predictive across a wide range of the population.
"Just because someone has a disease or is a certain age we shouldn't be categorising them as safe or unsafe," she said.
"I think it's important to give people the chance to demonstrate if they're safe or unsafe [on the road]."
She said people aged at different rates.
"Older people these days are very different to older people 20 years ago … they're really active, they're doing millions of things, they're keeping themselves physically and mentally well," she said.
The investigators hope the study could lead to the development of "interventions" focused on exercise or techniques to speed up reaction times to help older drivers remain safe, but more funding was needed.
"What we know is the consequence of taking away the licence is so bad and so negative unless they're prepared for it properly," she said.
"There are going to be some people who will very unsafe but I think there will be a big proportion of people who could be open to interventions.
"If someone values their independence they're more likely to undertake those interventions."
Professor Wood said the researchers had not investigated the effect driver distraction, satellite navigation devices and fatigue had on older drivers or the difficulties of parking, but she acknowledged they were factors that could be a problem.