Blind Cave Tetras are a relatively new tetra to the mainstream aquarium keepers. As there name would indicate, the Blind Cave Tetras have no eyes. They are born with eyes as fry, but the eyes degenerate and are reabsorbed back into the body at a few weeks old. There is a form that has eyes, although you do not generally see this version on the market.
These cave tetras are also completely devoid of pigmentation. They are pink, but will get an iridescent sheen to them as they get older.
The Blind Cave Tetra lives in deep caves in the wild. They range from Texas to Mexico, with the sighted version from Mexico to Panama. There is no need for eye sight in the pitch black caves, so they have evolved to adapt to these conditions.