Octopuses and their cephalopod cousins are famous for their ability to change colour and hide from predators and attract mates – but they can’t see colour, at least the way we see it. So why would a cephalopod bother dressing in bright hues if potential suitors can’t see them?
Earlier this year, we reported on a pair of researchers at the University of California, Berkeley, and Harvard University who found the unique pupil shape of cephalopods allows light to enter their eyes from many directions, which could help the animals interpret colour.
Cephalopods have evolved wide pupils, which increase chromatic aberration – the fuzzy fringe of colour you see around objects when your vision is out of focus.
By changing the “depth” of their eyeball, cephalopods can bring specific wavelengths of colour to focus on their retina. This allows the animals to change the amount of chromatic blur they’re seeing to determine different colours, depending on whether or not they’re focused on the retina.
Originally published by Cosmos as Are octopuses really colourblind?
Jana Howden
Jana Howden completed a double degree in Arts and Science at Monash University in Melbourne, Australia.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.
