(CNN)When three-year-old thoroughbred Patch takes to the starting gate at this year's Kentucky Derby Saturday, many people -- be it in the stands or watching on TV -- probably won't be aware that this is a very special horse.
At the left-hand side of Patch's head is a dark hole -- about the size of a golf ball -- where his eye used to be.
As a two-year-old, Patch developed an ulcer in his left eye that, despite the best possible medical care, didn't respond to treatment.
Eventually, in June 2016, the colt had his eye removed after trainer Todd Pletcher decided nothing more could be done to save it. Recovery
Trevor Breen rode one-eyed showjumper Adventure De Kannan to victory in the 2014 Hickstead Derby and he says the adaption for a horse after losing an eye is more of a mental than a physical one.
"I think the heart, mind and attitude of the horse are big factors in the recovery," Breen told CNN. "The first thing is the obvious one really, they've just got to come to terms with it.
"What they used to be able to see, they now can't. Horses are very good at adapting and I think they sometimes deserve a lot more credit than we give them.
"The key to it all is the mind of the horse. If they have a really good attitude and that they want to do the job that you want them to do, then they'll find a way to do it."
Patch, who was coincidentally given his name before losing an eye, is ranked as an outside -- but not impossible -- 30-1 shot along with three other horses.
Two other runners, Fast and Accurate and Sonneteer are given odds of 50-1.
That was the Number 2 Horse - THUNDER SNOW. All the meteorologists were betting on that horse. Since most of his races and practices were in the deserts of the UAE, Dubai & Qatar the slop was probably something he was not use to. AND they are THREE YEAR OLDS.