Eye patterns in the animal kingdom

Abstract

Eyespots are ring-shaped patterns similar to the lens eyes of vertebrates that occur in fish, reptiles, and insects. Behavioural experiments show that birds attack butterfly dummies less frequently when they display eyespots. Lens eyes sparkle which is caused by total reflection on the cornea. The sparkle appears in the upper part of the eye depending on the position of the sun. Butterfly eyespots mimic the sparkle. As birds respond with stronger deterrence to butterfly dummies that have a realistic position of the sparkling spot in the upper region of the eyespot compared to butterfly dummies with a less realistic position of the sparkling spot, lens eye mimicry can be assumed.