"It's a very rare form of cancer," he said. "It's very rare, but it's very treatable. We feel like we've got the best people in the world looking after the deal."
Petty said he hasn't been around the race shop much since November and hasn't done many sponsorship appearances since he and Lynda began "chasing this."
"After 50 years, I figured I better hang around a while," said Petty, who has spent his entire life traveling to racetracks. "Put that on the back-burner because I felt like she was a little bit more important than racing right now."
Petty said his wife was feeling much better after having surgery on both eyes. He left her briefly to come to Daytona International Speedway, where Petty has a record seven wins in the Daytona 500.
"I went in (Saturday) morning and she was jumping around and she said get up and get out of here and get over to Daytona," he said. "I know she's feeling pretty good from that standpoint. We're glad and we appreciate all the prayers and thoughts we've had for the family."
Lynda Petty is being treated at Duke University Medical Center and getting around-the-clock care with help from family members and nurses.
"They feel like they can completely wipe the cancer out," Petty said. "Naturally, it's going to take a little while to do it."