What if humans sight was akin to fantasy elves sensitivities to mana, “I may not have electro receptors like you but I'm able to to detect light with my eyes within the general vicinity” and they were so coy and vague describing light. Also if aliens have electro receptors imagine if they detect our nervous system. -- Anon Guest
The semi-amphibious Anatins didn't need to see light as they were evolving. They could sense the electrical discharges of predators and prey alike when they were close enough. That was enough of a sensory system to keep the species alive until they made it to the stars. After that things got interesting.
The first species they met outside of their own were Humans. Two exploratory crews more or less bumped into each other whilst attempting to get themselves out of a pickle and managed to successfully unpickle each other. It never takes much to get Humans to bond with you, but this one is a practically guaranteed method.
The Anatins were great at sensing creatures in the night, and therefore defending the impromptu camp from the beasts hidden in the foliage whilst the Humans kept away anything bold enough to get close. It was when the sun rose that the party discovered some key differences in sensory makeup.