Dawn of vision – And why blue light might be so special
Virtually all mammalian species exhibit some kind of circadian rhythm that affects their activities. These rhythms parallel the cycle of day and night and are, thus, in most cases linked to the perception of light. However, major surprises were in store for scientists, when they investigated whether mutant mice, lacking the well known image-forming rod and cone cells in their retinas, still possessed a circadian rhythm. —>—>
Fish without eyes
It is sometimes quite shocking what some people think the work of an animal biologist consists of. One day, when visitors to our house took a look at my aquarium and admired the fish in it, my ears had to hear the following comment: “Very interesting, but doesn’t it hurt them when you remove their eyes?” “What do you think?”, came my reply, “they are blind fish. They never have any eyes! They are Mexican cave fish, Astyanax mexicanus.” Stupid visitors (I did not say that), but they obviously did not know that some species of fish are naturally eyeless.
“Fly eyes are the better to see you with”
When Little Red Riding Hood in the Brother Grimm’s fairy tale of the same name asked the big bad wolf: “But Grandmother, what big eyes you have,” the wolf replied: “The better to see you with, my dear”. But there was no suggestion that the wolf had horny eyes. And wolves in Malaysia (if there ever had been any) also would not have them. However amongst the many truly weird looking insects that occur in Malaysia there are the “Stalk-eyed Flies” and these flies, as their name suggests, do possess eyes at the end of surprisingly long stalks which project laterally from their heads like the horns of a Watusi cow. —>