Blind fish are species that have adapted to life in dark environments, such as caves or deep ocean waters, where eyesight is not beneficial. These fish have evolved to lose their vision over generations, relying instead on other senses like touch and smell to navigate and find food. One well-known example of blind fish is the Mexican tetra, which can be found in underground rivers and caves. These fish exhibit unique adaptations, such as enhanced lateral lines, which help them detect vibrations in the water, allowing them to thrive in their lightless habitats.