Australian golfer Jeffrey Guan has vowed to return to the sport and “conquer any obstacle” after he was struck in the face by a golf ball and completely lost sight in his left eye.

The incident occurred in September during a pro-am tournament at Catalina Golf Club in the Australian state of New South Wales, only a week after Guan’s debut in the PGA Tour.

The 20-year-old rising star, a two-time junior national champion in Australia, said Thursday on Instagram that he was struck by the ball as he turned toward his golf cart to put his club away after taking a shot.

“The instant ringing and pain rushed to my head, and I dropped to the ground,” Guan wrote. “Voices sounded pretty muffled, and the next thing I knew, I was in an ambulance being transported to a hospital.”

He was then airlifted to Canberra, the Australian capital, to undergo surgery.

“I was in unbearable pain, and anxiety about my future was swirling in my mind,” he wrote.

After being transferred to Sydney for a second surgery, Guan spent two weeks in intensive care to make sure his eyeball was stable.

Any activity that required energy, including walking and eating, would leave him in “excruciating pain,” he wrote.

Guan said doctors told him there were multiple fractures to his eye socket.

“During my nights in hospital, I almost drowned in thoughts about the injury and my future in the sport,” he wrote, adding that “the whole situation made me very depressed and somewhat angry.”

PGA of Australia said Thursday that Guan’s vision loss was permanent.

Guan thanked those around him for all their support, saying “I will be back.”

“These four weeks have been the toughest of my life, but I am stronger mentally and will be ready to conquer any obstacle in the future,” he wrote.

As of Friday, a crowdfunding campaign launched by the Australian Sports Foundation had raised more than 13,000 Australian dollars ($8,500) out of a goal of 500,000 dollars.

Guan’s first PGA Tour appearance was at the Procore Championship in California in September. Though he missed the cut, “just competing in the event was a massive accomplishment,” Golf Magazine wrote.

He had recently signed a deal with Sportfive, a sports marketing company based in Germany that also represents Spanish professional golfer Jon Rahm.

This article first appeared on NBCNews.com. Read more from NBC News here:

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