A 21-year-old who demonstrated in Santa Ana, California, last Friday against the shooting death of Renee Good in Minnesota says exercising his right to free speech nearly cost him his life after a federal agent shot him with a less-lethal round — and that he now can't see out of his left eye.

"Not even light and I never will," Kaden Rummler told CBS News, explaining the extent of his injury. 

At one point during the protest, which turned chaotic, a federal agent could be seen on video pulling a protester from the crowd. That was when Rummler, holding a megaphone, rushed toward the agent and protester, and was then shot in the eye with a less-lethal round at close range. 

Video shows an agent dragging Rummler from the scene with his face covered in blood.

"I just started feeling like a bit of warmth down my, my face," Rummler recalled.

Rummler said doctors found plastic, metal and glass throughout his eye. He said metal is still lodged in his face a few millimeters from his carotid artery.

"My doctor said it's a miracle I'm still alive," Rummler said

The Department of Homeland Security has not specified what type of round struck him.

Rummler said he's "replayed that night so many times" in his head, "especially at night when I try to sleep, it keeps me up."

The Department of Homeland Security said in a statement that two officers were injured in a "highly coordinated campaign of violence."

Rummler was charged with disorderly conduct, but said he would "go back and do it all again in a heartbeat."

"I won't sit back when there's injustice going on," he said.

John Washington, Rummler's attorney, called it a "completely unacceptable use of force."

"There's a distinction between when an officer is genuinely threatened and a situation like this," Washington said.

Former NYPD detective Sgt. Felipe Rodriguez offered a view from law enforcements' perspective, saying, "Imagine having to arrest someone and also keep an eye on someone that's coming quickly upon you."

"He had very little time to react," Rodriguez said.

"We're not out there to hurt people but at the end of the day, we're not out there to get hurt either," he added.