CHARLESTON, S.C. (AP) — A group of eye doctors in South Carolina and a state law that limits where mobile clinics can operate are preventing a national nonprofit from providing free prescription glasses to thousands of low-income students in Charleston.

Vision to Learn has donated 240,000 pairs of glasses to children across the U.S. since 2012 and has mobile clinics in 10 states, The Post and Courier reported. Eye doctors in other states have resisted the nonprofit’s work before, but a South Carolina statute that only allows these clinics outside health care facilities creates an added barrier.

Retired banker Henry Blackford has raised hundreds of thousands of dollars since 2018 to introduce Vision to Learn along the state’s coast, according to the newspaper. Despite the South Carolina Optometric Physicians Association asking lawmakers to keep the law in place, Blackford wants it changed.

“What gets me is the program is operating very successfully in Charlotte and in Atlanta. It’s frustrating,” he told The Post and Courier. “The optometrists have been a huge stumbling block. Then we ran into the pandemic.”

The state optometrists’ group said in a statement provided to The Post and Courier that it opposes the fact that Vision to Learn doesn’t dilate students’ eyes during exams.

“While we are not opposed to the idea of mobile clinics, it does raise serious concerns regarding the quality of care that would be provided,” the association wrote. “In the absence of a dilated exam, the chances of missing serious medical conditions and issuing inaccurate glasses prescriptions goes up substantially.”

The S.C. Board of Examiners in Optometry prevented the nonprofit from hosting a mobile clinic in 2019 for the same reason, The Post and Courier reported.

An opinion issued by the office of South Carolina Attorney General Alan Wilson in January 2020 said Vision to Learn could distribute prescription glasses to students without violating the state’s rule. Wilson’s office wrote that the state’s Board of Examiners in Optometry called for dilation during an eye exam, but the Legislature didn’t require it.

Blackford told the paper that he believes the optometrists’ association fears for-profit mobile clinics could hurt their business model in the future if the law were changed.

Two Republican state representatives from Charleston wrote a bill in February that would allow nonprofit mobile eye clinics outside Title 1 schools. With the legislative session nearing an end, it likely won’t be discussed before next year.

The state Senate this week amended its version of the annual budget — which will be negotiated and voted on in May — to permit such clinics for a year.