How does the starfish see despite having no eyes? 

You must have been fascinated as well as intrigued since the time you heard about a star-shaped marine animal, right? Trigger for curiosity for many a marine life lover, we are talking about the adorable starfish here, also known as sea star. Did you know that a real-life starfish doesn’t exhibit any visible body part that looks like eyes? So, when cartoons portray a starfish with eyes at the centre (remember Spongebob Square Pants?), it is a false depiction. But then, how do they see? Are they blind? Let us find out. 

Spotting the eyespots  
From the surface, it may appear that sea stars have eyes, however, the truth is, they don’t. They do not have what we understand as eyes, to be precise. Instead, they are gifted with something called eyespots. While eyespots do not function like traditional eyes do, they can very well detect light and darkness. But where are these eyespots located and why can’t we see them? 

These eyespots are located right underneath the skin of sea stars, more specifically at the tip of their arms. Since starfish is a five-armed creature (like that of a star), it has at least 5 eyespots. As a matter of fact, these eyespots can be seen with naked human eyes only when an individual gets an opportunity to hold a starfish closely. Now, a starfish tends to tilt upwards when exposed to touch. When it does so,  simply look closely at the tips under their arms. There should be visible dots, in red or black, aka the eyespots.  

How do eyespots function? 
The starfish is itself a small organism. Therefore, it is obvious that its eyespots are really tiny. In fact, a starfish has eyespots that are only about half a millimetre wide. These are made up of hundreds of light-collecting units and almost look like compound eyes of insects (minus the lens to focus the light!). As a result, starfish can only detect light or darkness and at times other very large structures like coral reefs. Otherwise, they have no real sense of vision.  

Starfish not only have unconventional eyespots for detecting light and dark, they are also colour blind Since their eye function is too slow, they can hardly detect any fast-moving object, say for instance an aggressive shark. But nature is kind. Since the eyespots are located on each of the arms of sea stars, they have a 360-degree view of their surroundings, much more than we humans or any other animal for that matter! Scientists assume that this is how sea stars locate their preferred place of feeding and breeding. Fascinating creatures and even more fascinating vision stories, isn’t it?