One in four Scots surveyed by You Gov for sight loss charity RNIB and Specsavers still didn't know that eye examinations are free in Scotland.
The charity is marking National Eye Health Week, which begins today, by emphasising the importance of getting your eyes checked regularly.
RNIB Scotland director Campbell Chalmers said: "These routine check-ups can often pick up on the early signs of sight problems when there's still time to arrest or even reverse them.
"We know that making eye examinations free has already saved people's sight as well as sometimes picking up the symptoms of other conditions such as diabetes and high blood pressure. So it's vital that problems are picked up as early as possible.
"But it is worrying that, ten years on, some people aren't aware how important it is to get your eyes checked every couple of years. Sight is the sense most people fear losing most. And yet we can be surprisingly complacent about our eye health. We tend to think of eye examinations as something to do only when we want new glasses or contact lenses. But we should all get our eyes checked every two years, especially those aged over 40 and people of African-Caribbean descent.
"While an eye examination won't cost you a penny, missing out on check-ups could cost you some or all of your sight."
Nicola McElvanney, chair of Optometry Scotland, said: "It has been ten years since the Scottish Government introduced NHS-funded eye examinations. This is an important part of people's general health and wellbeing. A regular eye examination can detect not only ocular problems that could lead to preventable visual impairment, but can also detect other undiagnosed systemic problems.
"Optometry Scotland would like to embrace the publicity generated by National Eye Health week to encourage all members of the public to visit their optometrist for regular eye examinations."
Around 180,000 people in Scotland have significant sight loss, and the number is likely to increase given we have an ageing population and the incidence of sight-threatening health conditions such as diabetes is on the rise.
Any high street optician will do these short, simple eye examinations. Just ask for an appointment.