One in 10 New Zealand school children need glasses but don't have them, according to Auckland University's Optometry School.
Its students have tested four and half thousand kids’ eyes in the last year, as part of their degree.
"[Ten per cent] still sounds high in a developed country, that we have children that have visual problems, that we could help with, given there is this link between vision and educational outcomes”, said Professor Steven Dakin, Head of the School of Optometry.
Twenty per cent of the kids screened as part of the programme failed and were sent home with a note to visit the optometrist.
Of those, half went on to get glasses.
Sudent optometrists told 1 NEWS they’re surprised at the need.
"It's only when you start delving in and asking those questions you kind of pick out they’re having issues," student Kavin Natali says.
Professor Dakin says: "Children need to be able to see well in order to be able to learn."
"It would be hard to overestimate the value of good visual correction for children, in terms of fulfilling their lifelong potential."
Mount Roskill Primary is one of the schools where screening is carried out annually.
Deputy Principal Sonya Lamb says: "You can't put a price on this, it's fantastic field work for the optometrists, but also for our kids it's about removing barriers to learning and it's such a simple thing to do".
All children have their eyes tested before they start school, but the next official test isn’t until intermediate school.
Professor Dakin says that's an issue as "it’s a long gap".
The school screening programme run by the university helps but is only offered in Auckland, and not at all schools.
"We are fundraising to try and purchase New Zealand's first mobile optometry unit… and actually travel within and outside of Auckland to deliver screening services and full comprehensive eye examinations to as many children as we can," Professor Dakin said.
It is thought the proposed vision bus would triple the size and reach of the current screening programme.