Can Fish See Colour?

One of the many good questions we were asked at our recent shows stuck in our heads: “can fish see in colour?”  With a bit of research, we found some very interesting information about fish’s vision:

  1. Unlike our eyes, the lens of a fish’s eye does not change shape to focus, it moves forward and backwards, like a snake’s eye.
  2. The fish’s iris cannot contract and dilate like ours. The rods and cones in the back of the fish eye change their shape in response to changes in light.
  3. Fish can have up to four different cones in their eyes (humans have three types of cones), one of which detects ultra-violet light. Other fish have no cones, only rods, so cannot see any colour at all.

So, to answer the question: some fish can see more colour than we can and some cannot see any colour at all.

You can learn much more about fish vision at All You Need is Biology