Marc Benioff-backed Gobiquity, which makes a vision screening app for children called GoCheck Kids, has raised $6 million in a round led by existing investor Interwest Partners. The company, formerly known as iCheck Health, previously raised an undisclosed strategic investment from Benioff and a $750,000 seed round from Interwest.

Gobiquity officially launched GoCheck Kids last November. The company began rolling out the product to pediatric practices at the end of 2014 on handheld devices that were issued to practices, then gradually added more functionality prior to the official launch, which allows physicians to download the app on their own iPhone or use it on a preloaded handheld device.

GoCheck Kids screens for amblyopia, a functional disorder of the eye that typically comes from squinting and can lead to severe visual impairment. Since the November launch, 2,000 US pediatricians have used the app, the company said in a statement. In addition, more than 100,000 screenings have been performed, and an average of 3,000 children are screened with the app per week, which represents over 300 percent annual growth for the company.

“InterWest Partners continues to support our mission to enable early detection and prevention of vision impairment through broad access to specialized mobile technology,” Andrew Burns, CEO of Gobiquity, said in a statement. “At Gobiquity, we are committed to evolving our validated, portable and affordable mobile screening portfolio to address both children and adults.”

Right now the device is only for doctors to use, but Burns suggested in a statement that recent app updates are setting the company up to make the app available to caregivers as well. 

"We are excited about this release because it provides us with more opportunities to detect and prevent vision impairment for a market of more than 285 million people who suffer from vision impairment, of which 80 percent is treatable if identified early,” he said.