Underwater vision

Biologist, vision scientist of non-human creatures and retired optometry lecturer, Professor Ron Douglas, took to the stage at the Hospital and Specialty Optometrists Conference (HSOC) last month to talk about the vision of aquatic animals.

Hosted at the University of Warwick over two days (November 4–5), Douglas’ CPD-accredited lecture explored the various ways the visual systems of aquatic organisms, such as scallops, shrimp and octopus, can provide solutions to ocular questions.

Speaking to OT, Douglas explained that the aim of his talk was to try and demonstrate to a clinical audience that “there are many ways of seeing and many facets of vision which humans don’t have.”

“[I think I] secretly wanted to convince [people] that the eyes of other animals are more interesting and arguably better than humans,” he added.

Douglas emphasised that “we can miss a lot if we concentrate on specific subjects in humans,” adding: “The things that I have found out using deep sea fish, now having clinical trials and interest in the military… all sorts of things fall out of it, and we would miss a lot if we only tried to answer specific questions in humans.”

One aspect of vision that Douglas discussed during his See food cocktail talk was colour vision. Emphasising the breath of learning in this area that can be taken from deep sea creatures, he highlighted that while goldfishes have better colour vision than humans, with four vision pigments, the Mantis shrimp has 13 different colour channels, “giving it indefinitely better colour vision most likely than you could possibly imagine.”

When asked by OT, Douglas selected the dragonfish as one of his favourite animals. He shared that one of the reasons he finds the creature interesting is because it has chlorophyl in its retina that comes from bacteria, and it is the chlorophyl rather than the visual pigments that absorbs the light. “No other animal is known to have that sort of vision,” he said, adding that it is turning out to potentially have clinical applications.