Featured Image Credit: Inquirer.net
By: Katie Gillis
Dory’s back with a whole slew of new and old friends in the hit sequel “Finding Dory.”
One of the most memorable characters in the movie, a young whale shark named Destiny, won over our hearts with her quirky clumsiness.
Destiny’s clumsy charm seems to be attributed to poor eyesight. She gets quite frustrated with her near-sightedness, especially when she keeps running into the walls in her enclosure!
Photo Credit: Source
This makes us wonder, do all whale sharks have poor eyesight, or was Destiny an oddball in a sea of sharp-sighted sharks?
Sharks have pretty cool eyes. They are composed of a cornea, iris, lens, and retina, much the same as humans. But sharks can take it to the next level.
Shark eyes contain a special tissue, tapetum lucidum, which allows for more enhanced underwater vision. Since sharks live in the water, this does make a lot of sense.
This special tissue, comprised of mirrored crystals, enables the shark to contract and dilate its pupils, similar to how people can. However, instead of the light being absorbed, it is reflected back to the retina, allowing for far superior vision in darker conditions out in the deep ocean.
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Sharks also have the ability to change their vision from stereoscopic, or 3D vision like ours, to monocular vision. Monocular vision uses just one eye and limits depth perception, but increases the quality of the image.
Sharks can change their vision back and forth at will and since their eyes are on either side of their head (in most species), they can almost get a 360-degree field of vision.
So where do whale sharks fit into all of this?
Although whale sharks are the largest fish in the ocean, they actually have really small eyes. Their eyes are tiny and circular, and are positioned laterally on the shark’s blunt head. This suggests that they have a wide field of vision.
Photo Credit: Source
Unlike some other shark species, whale sharks lack eyelids. However, their eyes can rotate, close, and can be drawn back into the head for defense. Whale sharks have increased sensitivity to low-light environments, which makes sense seeing that they spend much of their time in the deep abyss.
Whale sharks have been observed picking out swimmers and following them at fairly close distances of three to five meters. They have also been documented to single out objects and movement at close range.
All of these findings seem to support Destiny’s claim of being near-sighted. So, maybe she isn’t so odd at all. Instead, she is as normal a whale shark as they come. Maybe once she reaches deeper waters, she will see more clearly!
Seems like Disney was onto this the whole time. Guess we will just have to wait for another underwater sequel to find out more!