The biology of imaging.

On the cave wall, a discrete but stunning silhouette runs across the uneven surface. Standing still for more than 45 000 years, this is a witness to the ever-enduring need of mankind to image the world around us. The biological world that feeds us is a primary source of inspiration but also an essential element to creating the imaging systems we use every day. But once obscured by the technological jargon and the thunderstorm of numbers and algorithms, those origins fade away into the background. This small piece is about a few marvellous little stories about the biology of imaging, not the debate about the origin of vision and the eye but rather about plants and animals that open the world to new dimensions of biological imaging to fully image the biological world. An eye for an eye. This article is part of the Theo Murphy meeting issue 'Super-resolution structured illumination microscopy (part 2)'.