Australian golfer Jeffrey Guan has vowed to return to the sport and “defeat any obstacle” after he was hit in the face by a golf ball and lost all 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, just a week after Guan’s PGA Tour debut.

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

“Instant sound and pain rushed through my head and I fell to the ground,” Guan wrote. “The voices sounded quite muffled and the next thing I knew, I was in an ambulance being taken to a hospital.”

He was then flown to Canberra, the capital of Australia, to undergo surgery.

“I was in excruciating pain and anxiety about my future was running through my mind,” he wrote.

After being flown to Sydney for a second surgery, Guan spent two weeks in intensive care to ensure the 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 the orbit.

“During the nights I spent in the 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.”

Australian PGA said Thursday that Guan’s sight loss was permanent.

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

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

From Friday, a crowdfunding campaign launched by the Australian Sports Foundation has raised more than A$13,000 ($8,500) of a $500,000 goal.

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

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

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