Seeing in the dark
The weird story of elephantnose fish
Until year 2000, elephantnose fish were thought to be blind or nearly so. Now we know they have peculiar eyes that are well adapted to see objects in the dark and muddy waters where they live, and their eyes have been used as model to build artificial eyes that can see in the dark.
Elephantnose fish is an african freshwater fish; it can be kept in aquarium and, in the aquarium standard conditions, this fish is basically blind. However, the aquarium standard conditions are very different from its natural environment. It lives in slowly moving muddy rivers and its eyes are well adapted to see relatively big objects (such as predators) in this dark environment.
The structure of the elephantnose fish eye is unique among vertebrate animals, it is made of many tiny crystal cups that collect and intensify the light. This structure has been used as model to build artificial eyes that can see in the dark. So far, most of the work trying to improve the night vision of image-taking devices has been on to the sensitivity of the detector. This new artificial eye, mimicking the elephantnose fish eye, enhance the intensity of the incoming light before the detector.
There is nothing new from emulating structures of living animals for building artificial devices. It has been done for ages. Any way, we are now using as model the eye of a fish that was thought to be blind just few years ago. There is always so much still to know.
Information are from: Liu H., Huang Y., and Jiang H. Artificial eye for scotopic vision with bioinspired all-optical photosensitivity enhancer. Proceedings of the National Academy of Science of the USA, vol. 113, pp. 3982-3985 (2016), and from this podcast.
Picture is from http://opencage.info/pics/large_19259.asp