Do you know what spec, vis and vid have in common?
Well, they are simply Latin roots from which a number of modern English words, related to the vision and the ability to see, come from. As a matter of fact, we have words such as spectacular, vision, video (you get the picture). Another relevant example could be the verb conspicio, also Latin, which stands for catch sight of, therefore we end up having a literate word as conspicuous. But that’s enough for the language matters and origins.
Vision is vital for the survival of species, but it also helps us understand and get to know the world that surrounds us and the eyes (or oculi in Latin) are here for us. The aim of this post is to provide some quirky information about the different types of eyes as opposing human vision to animal vision (including insects and fish).
Human Vision
We’re lucky that we can differentiate colours, fine details, interpret visual signals and adapt to our environment. Our visual acuity, or the ability of distinguishing details (the clearness of vision in other words) is pretty high and this is due to the presence, thankfully, of cone cells. Cone cells are responsible for the colour vision. There are 3 types of cone cells regarding the perception of light – long-wavelength light(or red), medium-wavelength light(green) and short-wavelength(blue). The combination and the interpretation of which allow us effectively to perceive colours as a result. But if we are sensitive to colours then we can also deal with the perception of black and white, or monochrome, vision. The cells that make the black and white vision possible are the rods (like cone cells they’re sensitive to light, although a different type, and from that respect they’re called photoreceptor cells). The rod cells help us adapt to dim light, even though our night vision is not that sophisticated as in comparison to that of nocturnal animals (e.g owls, bats) and some deep sea creatures (e.g dragonfish and fangtooth, bizarre names for just as bizarre looks).
Animal Vision
Did you know that flies, among other insects, have compound eyes? Compound eyes are formed of multiple, tiny lenses that have the structure of a honeycomb. The compound eyes provide a very large view angle and can detect fast movement (now you know why it’s really hard to catch a fly).
How about sharks, one of the biggest predators in the world?
Sharks’ eyes have rod and cone cells (just like us, however it still remains unclear how sharks perceive colours), pupil, retina, lens and iris, but sharks’ underwater vision is 10 times better than ours, unsurprisingly though. This is due to the tapetum lucidum, a tissue composed of mirrored crystals. What seems to be worth knowing too is the fact that sharks have eyelids, similar to ours, but they don’t necessarily use them to protect their vision. Instead, a delicate membrane will cover the entire eyeball, especially when sharks fight with their preys. The great white shark, however, will roll its eyes back in its head for protection during violent encounters.
Do you like scallops?
These sea creatures are member of the mollusc family, just like squid, octopuses and cuttlefish and the unusual fact about them is that they have up to 100 simple eyes. The simple eye refers to an eye that possesses only 1 lens, however its function is far from simple.
So, given that spectacular information the points of view are merely the reflection of how we, and others, perceive the world.
Yours visually,
Velizara
*Featured image by Stephanie Pearl – you can follow her on Facebook here.