>>13844238Under certain circumstances, it can be an advantage because in certain environments where it's impossible to see anything, having a highly developed visual system is useless. There's no evolutionary pressure to develop one because it offers no advantage.
They probably "see" a little bit with their eyes though, but only to the level where they can tell if it's light or dark. Regions of the brain normally devoted to the eyes are probably highly devoted to other senses such as sound, and they likely have really highly developed hearing. And because of how their brain is allocated differently due to a lack of vision, they're experiencing vision as we know it through their ears.
It's more advantageous to prioritize senses that will gather the most information about their environment, and it's the brain that is THE sensory organ. Eyes, ears, skin, whatever, just take in information from the environment. The brain turns that into a sensory experience.
If humans lost their eyes but kept their highly developed occipital lobes, they would continue to experience "seeing". That's exactly what would happen if humans somehow evolved in caves with zero light where eyes were useless instead of out in the open where seeing was a massive advantage.
