She didn’t set out to be the first Black woman to invent or achieve a feat. But she did that and more.

In fact, Patricia Bath became the first person — not woman — to invent and demonstrate laserphaco cataract surgery in 1988. And she didn’t let the surprise from her colleagues that a Black woman could change the medical world forever dampen her achievement.

In fact, she never doubted herself at all.

“I went to a prominent institute in Orange County and explained to the director what I had achieved,” she wrote for TIME Firsts, a multimedia project on 46 trailblazing women who are changing the world. “He said, ‘That’s impossible. People have been trying to do that for years.’ He didn’t believe me. A month or so later, after my patent had been granted and I published the findings, he was shocked. He wouldn’t look me in the face.”

But even though Bath knew her worth and power before those around her began to see her brilliance, she is at times humbled and grounded by what she’s contributed to society.

“One rainy, cold, lonely night in the lab, we had a donor eye. The laser was finely tuned, the optical fiber was in position and … Eureka! I knew that I had made a scientific breakthrough in removing cataracts,” she wrote. “Sometimes even now when I’m told I was a ‘first,’ it comes as a surprise, because it’s only through history that you understand that kind of thing. I didn’t realize when I joined UCLA in 1974 that I was the first woman in the ophthalmology department. I simply wanted to be part of a great team at an incredible facility. I wasn’t seeking to be first. I was just doing my thing, and I wanted to serve humanity along the way—to give the gift of sight.”

We celebrate Bath for her contributions and her persistence to create a safe space for women in the medical field. Bath’s interview is part of TIME Firsts, a multimedia project featuring 46 groundbreaking women. Watch the rest of the videos at Time.com/Firsts. Buy the book at the TIME Shop.