Blind.

On the other side of the Galaxy there is a planet, Euterpe, not all too different from the Earth. Similar temperature, similar age, water on its surface, and life of comparable diversity. But its mass is greater by three fold, and its surface gravity is twice the Earths. This holds down a very heavy atmosphere, which makes life on its surface quite different from the Earth. First, the stars light is dim and often often obscured by clouds, and second sound travels with superb clarity. It should be of no shock that creatures fit for comparison to human came to live on the planet. There shape I do not know, but I envision them as stocky men with beady eyes, large bat like ears, and stony flesh. Their eyes are only developed enough to see fields of colored light, but not shape specifically. But their ears are amazing, nothing on Earth, save maybe MAYBE the great whales have hearing that approaches theirs. They hear the shapes of their surroundings and they live in a world of pure sound.


When they emerged as a species on this planet they were a quick success, they were clever like humans. It a short few myriads of years they came to cover the land mass of the planet. One group small group sought to understand the world. So they blinded themselves. At birth a child's eyes would be cut out. To us this sounds drastic, but it was perfectly rational. You see their eyes weren't useful, they were only good for watching the bioluminescent displays of lower lifeforms; and this was a diversion that the youth would easily lose themselves in for days at a time if not cut. Their eyes were their weakness it seems, they were vulnerable to hypnosis by flashes of light that other creatures could produce. By blinding themselves they were free from this ancestral vulnerability, free to listen to things to learn their structure and their properties. And this group did learn, and did become powerful from their knowledge. And they spread over Euterpe teaching their ways to the 'lightstruck' those still afflicted with sight.