Ronaldo initially played on after being patched up on the side of the pitch and scored Real's 21st-minute opener in a 2-1 victory. But he had to be replaced at halftime after suffering problems with his vision.
"It was an accident, at no time did I try to cause harm to Cristiano Ronaldo," Navarro, who has a history of violent conduct, said on Levante's website.
"These are things that happen during a game and I regret having wounded him, but I repeat that it was something completely involuntary," the 32-year-old added.
Other incidents include an horrific studs-up challenge on former Real Madrid midfielder Luis Figo and an off-the-ball stamp on Barcelona forward Lionel Messi's ankle.
Ronaldo will miss Portugal's friendly in Gabon on Wednesday as a result of the wound, the country's football federation (FPF) said on Monday.
