Getting our teeth checked regularly is something most of us do every few months, but what about your eyes?
The Eye Care Trust charity reckons up to one million kids under the age of 12 could have problems with their eyesight without even knowing about it.
Now a campaign's under way to encourage everyone under 12 to make use of the free and simple eye tests on offer.
About 150,000 pupils across the UK will also have lessons about eye health as part of the Eye Know Eye Care campaign.
Experts say you should be getting your eyes tested every two years.
Optician's advice on eye tests
Not being able to see clearly can cause lots of problems, but having an eye test helps opticians work out the best way to help you.
Eye tests involve quick and easy tests, like getting you to read different sized letters and seeing whether you can tell the difference between different colours.
Some schools offer eye screenings, but many don't.
Ten-year-old Vanessa found out she needed glasses after she started making mistakes in class.
"It was frustrating because I was getting questions wrong in class but then I found out why," she said.
"Don't be worried about going to the optician - it's not really scary just stay calm."