For other animals, an eclipse-induced Purkinje effect may be even more intense, says Freya Mowat, an assistant professor of ophthalmology at the University of Wisconsin–Madison School of Veterinary Medicine. Birds have a fourth cone that lets them see ultraviolet light. It’s difficult to say exactly how the sudden light change during a solar eclipse would affect avian vision, Mowat, says but it’s possible that the shades of purple would be extra vivid and disorienting