Kids get conjunctivitis for different reasons.
Bacteria are smaller than the head of a pin and can only be seen with a powerful microscope. They live on your skin all the time and you never know it. Most don't ever bother you, but certain kinds of bacteria can cause infections like conjunctivitis. Sometimes kids get ear infections when they have conjunctivitis because the same bacteria can cause both problems. Kids also get conjunctivitis because of allergies or because they get something irritating in their eyes.