(CNN) -- Bethany Storro doesn't usually wear sunglasses, but she got a surprise paycheck and bought a pair earlier this week. Those sunglasses, she is convinced, saved her eyesight when a woman threw a cup of acid in her face 20 minutes later.

"God is watching over me," Storro, of Vancouver, Washington, told CNN affiliate KATU in Portland, Oregon. "I believe in him. That his hands are on me and I can't live the rest of my life like that -- in fear. I can't let what she did to me wreck my life."

Storro is hard of hearing due to a childhood virus, so her sight is especially important to her, particularly because she can read lips.

Vancouver police say they are looking for the assailant, described as an African-American woman with an athletic build and slicked-back hair pulled into a pony tail.

Storro told KATU that she had stopped at a Starbucks about 7:15 p.m. Monday, just after she had gone back to buy a pair of sunglasses that she had seen earlier. The woman walked up to her and said, "Hey pretty girl, do you want to drink this?"

When Storro declined, the woman threw the contents of the cup in her face and ran off.

"When I first saw her she had this weirdness about her, like jealousy, rage," Storro said.

Storro underwent surgery at Legacy Emanuel Hospital in Portland, where she held a news conference Thursday with her head covered by bandages.

Storro said she spoke about the attack because she wants people to see what the woman did to her and to help authorities find the woman before she assaults someone else.

Still, she has questions about the senselessness and seeming randomness of the attack.

"Why did you" do that, Storro asked. "Did you wake up that morning and go, 'I'm going to, I'm going to carry some acid in a cup and throw it at the first person that I see?' Was it a dare? You know, why me?"

Speaking with her parents by her side, Storro described the pain she felt.

"Oh, you don't even know!" she said. "It was the most painful thing. Like I told everybody, my heart stopped. I almost passed out. It's like, imagine -- I mean, it ripped through my clothes the instant it touched my shirt. I looked down and it just ripped through my shirt and made holes in my shirt.

"So imagine that on your skin. I could hear it sizzling. Once it hit me, I could actually hear it bubbling and sizzling my skin."

Doctor aren't sure yet how bad Storro's face has been damaged because she's just starting to heal.

But the attack does not seem to have hurt the woman's spirit.

"I try to stay positive, and there's moments when I get really frustrated, and I want to get mad at somebody," Storro said. "But there's nobody to get mad at, you know."

Vancouver police, who released a composite sketch of the suspect, ask anyone with information to call Major Crimes Unit Detective Wally Stefan at 360-487-7425.