Whether the diagnosis is type 1 or type 2 diabetes, the CDC says diabetics have a greater risk of developing visual impairments, including blindness.
Still, many disregard their doctor's recommendation for an annual eye exam.
Now, thanks to a local program, if they won't go to the doctor, the doctor will come to them.
About 25 patients - mostly diabetics - were screened on the Columbia Lighthouse For The Blind's new Mobile Eye Care Van.
The organization has partnered with the Holy Cross Hospital Health Center in Silver Spring - to serve uninsured and underinsured adults who might not visit an eye doctor otherwise.
Health center director Marlene Printz said," A lot of our patients, if they're working, they're working two, three, four jobs. They're taking care of their children. They're taking care of their neighbors' children.
On the van, optometrist Jenny Chan screened patients for diabetic retinopathy.
According the National Eye Institute at NIH, it's the most common diabetic eye disease and leading cause of blindness in American adults. It occurs when blood vessels in the retina swell and leak fluid.
In the early stages, there are often no symptoms or pain. But over time, diabetic retinopathy can lead to permanent vision loss, unless it's caught and treated.
Chan said, "[Doctors] can put an injection directly into the eye of some medications that can stop the bleeding. They can also take some lasers to seal off the blood vessels to get that bleeding to stop."
During her screening, diabetic Francess Nicol learned she was showing early signs of diabetes in her eyes and she was referred to a specialist.
"I'm not scared," Nicol said. "I know I'm going to be fine. As long as I keep my eye on it and I'm seeing a doctor, I'll be fine."