"I used to run events but when I lost my sight I didn't run at all," she said.
Warren-Bird said her loss of vision as "just a spontaneous retinal detachment".
"It just happened. There was no warning - one day I looked up at the computer screen and it was just flashes and lights and stuff," she said.
Warren-Bird went to the doctor who assured her the issue would be simple to fix with a hospital visit.
"Ten operations later - didn't fix it."
Warren-Bird can still see out of her other eye but the loss of full vision has cost her significantly.
"There was a lot of loss - loss of my sight, loss of my job, loss of my husband. All in one year - 2016. It was my annus horribilis."
Warren-Bird also lost her son in a motorbike accident at the beginning of that year.
"Yeah, it was a negative time. But then I joined Achilles."
Achilles International began in 1983 as the Achilles Track Club when founder Dick Traum, an above-the-knee amputee, became the first amputee to run the New York City Marathon. He wanted to provide that same opportunity to other people with disabilities.
Warren-Bird now regularly takes part in parkruns with the Achilles club, in addition to marathons in Wellington and Tauranga.
"Without Achilles, I wouldn't have had the confidence to do that," she said.
She admitted experiencing anxiety about "not being disabled enough" because she still had some limited vision "but they are so welcoming and open".
Warren-Bird described the charity group as "like family".
She said taking part in events such as the Rotorua Marathon meant a lot.
"It's just an achievement, getting to the finish line."
On Saturday, Warren-Bird wore a huge smile and a pair of colourful mirrored sunglasses during the race.
Suzanne Hardie, club administrator for the Tauranga Achilles chapter - to which Warren-Bird belongs - said people from all over the North Island were taking part and spent time getting to know each other the night before.
Hardie said events like the marathon had a huge impact on club members.
