Helmet gecko in daylight
A nocturnal gecko, the Helmeted gecko (or Tarentola chazaliae), that is native to the west coast of Africa, has caught the attention of Swedish researchers, who gazed into the eyes of the little lizard looking for the secret to his powerful and colorful night vision. What they found may help them to create better camera lenses as well as multi-optical contact lenses for human eyes.
The "helmet gecko" is extremely sensitive to light; that is why you see just a tiny portion of his pupil shows during daylight hours. Think about how bright sunlight causes us to squint and thenDay-active gecko compare the exposure of his pupil to the light with the day-active gecko's wide open pupil below.
Special equipment was made to examine the retinas of research geckos that
enabled the geckos to remain awake and unhurt during the studies, in compliance with the Swedish animal welfare agency.
Whereas most vertebrates have cones and rods in the retina that receive light, lizards have only cones in their retinas. Cones are more sensitive to light than rods, and are better at perceiving subtle differences in color than rods. What the researchers learned is that is the helmet's sensitivity to light is even more extreme, because the helmet gecko has several very distinct large concentric cones in its retina that focus light more intensely -- up to 350 times more intensely than the human retina.
Unlike other lizards, or even other geckos, the helmet gecko has a multifocal optical system whereby light at different wavelengths is perceived simultaneously on the retina. Their eyes can also focus on objects at different distances at the same time, which is unique to the helmet gecko. If we look at something close to us, like a computer screen, only that object will be in focus; but the helmet gecko can see at least two objects at different distances equally clearly.
Perhaps through biomimicry, camera lenses with equal clarity and color at several distances can be developed. It would great if the research also leads to a contact lense that could bring humans multi-focal ability... but I'm trying to imagine what that would do to our brains!
Journal of Vision via Eurekalert