Why Do Sharks Roll Their Eyes Back?

Sharks are fascinating creatures with many unique features like sharp teeth, a streamlined body, and a great sense of their surroundings. One of the interesting things about sharks is that they often roll their eyes back, which has made many people wonder why they do it. In this article, we will explore some of the reasons why sharks roll their eyes back.

Eye Protection

Sharks roll their eyes back to protect them. They have a third eyelid, called a nictitating membrane, that helps keep their eyes safe. By rolling their eyes back, the membrane covers and protects their eyes while they hunt or eat, which prevents them from getting hurt.

Vision Enhancement

Rolling their eyes back also helps sharks see better. When they do this, it exposes a part of their eye called the tapetum lucidum, which helps them see more clearly in low light. This layer also helps them spot prey more easily.

Gill Regulation

Another reason sharks roll their eyes back is to regulate the flow of water over their gills. Sharks need to keep moving water over their gills to breathe, and rolling their eyes back helps to direct water flow towards their gills. This behavior is particularly helpful for sharks that live on the ocean floor.

Emotional Communication: Body Language

Finally, sharks may roll their eyes back to show how they feel, like many other animals. They use their bodies to communicate with each other, and rolling their eyes back can indicate that they are relaxed or submissive. If a shark rolls its eyes back aggressively, it can be a warning to other sharks to stay away.


In conclusion, sharks roll their eyes back for several reasons, such as protecting their eyes, seeing better, regulating water flow over their gills, and expressing emotion. These unique behaviors show how sharks have adapted to their environment, and they continue to fascinate and captivate us. The natural world is full of wonders, and the complexity of shark behavior is just one example of its intricacy.