I'm so glad you asked this question... I didn't have a clue, so I researched it, and this is way cool stuff! By studying these blind cavefish, scientists are learning about genetic mutations which cause blindness. These studies show real promise in unlocking the key to genetic abnormalities which cause blindness and other birth defects in humans. For more, visit http://www.biology-online.org/articles/scientists_clue_blindness_cavefish.html
Blind cave fish are helping scientists better understand the adaptations behind blindness. Since they can give birth to fry that can see, they are giving scientists an insight into the genetics involved in human and animal blindness. This may help solve blindness issues in both humans and animals. Read on from en.wikipedia.org/wiki/Amblyopsidae.