The snail has their eyes at the ends of their stalks.

He believed it worked for him anyway, even though in the end he and his entire experience became “a little device sitting on someone’s table.” Maybe that’s enough.

As long as we’re coming up with overly convoluted reasons that a minor plot device from a fantasy space opera makes sense in a rigorous scientific way, why not assume that they were genetically engineered specifically as a torturous punishment for the Hutt syndicate? Bioengineering is apparently canon, so there’s in-universe justification.