vision in red

Ferrets have stereoscopic vision so their peripheral vision is good but beyond a few ferret lengths they can't see much detail. Close up, they will see in good detail but their sense of smell, hearing and touch are probably more important than sight. They have a reflective layer at the back of each eye (tapetum lucidum) so their low light vision is much better than ours. They can see red so Pan knows whose shoulder he's on here, apart from the smell of course.