Ah-ha, so they do know what he means! In fact it belatedly occurs to Rezo that they mentioned their own eyesight isn't very good, at least not in sunlight. Of course they'd have a better idea than most of how Rezo observes the world. Not a perfect understanding but it's still an odd notion to consider.

"It isn't helpful for everything, but it keeps me from running into any walls," he says lightly. "And drives off any carnivorous cows that might be roaming nearby."