Unlike the surface form, some of the cave-dwelling forms lack functional eyes, which regressed over evolutionary time since, in the absence of light, the blind fish in caves faced no disadvantage ...

Unlike fully blind cave fish, it may still rely on light cues to regulate its biological rhythms, a sign that it hasn’t ...

In cave systems, these can include cockroaches ... However, what is really interesting is there aren't any blind fish in the deep sea. No sunlight penetrates below 1,000 metres, even in the clearest ...