Our human senses are pretty incredible - but we only see, hear and smell a tiny fraction of what's out there. There is a hidden world that animals across the globe can experience. This episode explores the extraordinary sense of sight in the animal world. We travel through the colours of the rainbow, across the spectrum of light our eyes can see - and beyond.
Presenters Helen Czerski and Patrick Aryee reveal how caribou use UV light to avoid wolves, discover how seeing in slow motion lets dragonflies make a kill in the blink of a human eye and show how one animal can see in pitch-darkness - without using its eyes.