Being in a fight with an invisible attacker may sound like a nightmare. Christella Garcia, a medal-winning, blind Paralympian judoka, says it's "wonderful.""It makes perfect sense," Garcia told AFP right after defeating Brazil's Deanne Almeida for bronze in the over 70 kilogram category in Rio de Janeiro on Saturday.Garcia, who has been almost completely blind from birth, said out on the judo mat, where opponents try to outwit, unbalance and throw each other, her disability no longer matters."You're gripping and you feel your opponent's body and the way they're moving," Garcia, 37, said. "It about who wants it the most."Judo in the Paralympics is reserved for the visually impaired - some with limited eyesight, others like Garcia with virtually none. There are surprisingly few changes to the way the regular sport is played.Contestants unable to see the boundaries may unwittingly spill outside, so the referee has to guide them back. And unlike in regular judo, where the clock is visible, a loud buzzer goes off at the one minute warning before the bout ends.Otherwise, the combatants in their white or blue kimonos fight as skillfully and fiercely as those with proper vision. It can be easy to forget they are blind at all - until the incongruously gentle scene of a referee leading a black belt fighter around by the hand.Another US bronze medal winner Saturday, Dartanyon Crockett, only took up judo when he left high school. Learning a sport in which being propelled through the air or choked while lying on the mat are integral parts was not easy for a young man born blind."Part of doing judo for the visually impaired is putting yourself in a scary, uncomfortable situation," said Crockett, now 25. "It's about stepping out of your comfort zone."