Had to make one of these eventually.
I'm Ottertail1, or just Otter I guess. I like Warrior Cats, Polandball, Countryhumans, Wings of Fire, Hazbin Hotel, Solarballs, and Humans Are Space Orcs.
I'm a furry, so I guess that's a thing for me. I'm not a therian, no hate but don't get me confused. I go by She/Her, and I'm a straight ally.
That's kinda it. I would put an image here of my fursona but I don't have a digital full body drawing of them.
An Overanalysis of Human Eyes - Humans are Space Orcs
"The eyes are the windows of the soul" - Regiment of Life, 1553.
Human eyes are quite unique. Humans always have a visible iris, sclera, and pupil, all together. There are some medical conditions that can result in humans not having a pupil, however it's quite rare.
Humans also have a white sclera, with little to no visible blood vessels. The only time they become visible is when the human is on certain drugs, which is a different topic. This white sclera allows one to see where a human is looking.
Humans also have a colored iris. The most common color is brown. Brown has high melanin, which causes the eye to be darker, which absorbs more light. It also has more protection, which prevents glare from the sun.
Blue eyes are more adapted to low-light conditions. It enhances vision in dim conditions, due to the fact of low melanin does not block light. They often shift in color, having a lack of pigmentation results in a color that can range from blue to grey in color depending on lighting. They are much more sensitive to light, and can have damage from light.
Green eyes are the balance between blue and brown eyes, with a chemical known as lipochrome to give green eyes it's color. It allowed humans to live in conditions where the light ranged, not needing as much sensitivity as blue eyes, but not needing as much protection as brown eyes. Like blue eyes, they range in color depending on lighting, but stay green.
Hazel eyes are like green eyes, but less lipochrome. They are very similar in use to green eyes, and they highly vary from person to person, and they do range in color in lighting as well, sometimes appearing as different eye colors entirely.
Amber eyes are low in melanin, but high in lipochrome, giving them an orange yellow appearance. It's main use is the fact that it provides social advantage, like many other cosmetic traits in humans.
Gray eyes have even less melanin than blue eyes, which allows them to have even better vision in low light conditions. However, this comes at the cost of high potential damage from light and glare.
Black eyes have an incredibly dense concentration of melanin. They have almost no risk of damage by light passively, and stay stable in all sorts of light conditions. They conceal emotion.
Heterochromia is the condition where someone has two different colored eyes. They are incredibly rare, caused by localized mutation, uneven pigmentation, and many other non-understood biological reasons, and can even be caused by injury.
Moving onto pupils, they are fascinating. Human pupils are quite small, most other earthen species have pupils that take up nearly the whole eye. This causes the light to enter at one point in the eye, instead of the whole eye. This allows for better distance vision, but smaller vision that's in focus. Human eyes make up for this in motion. Eyes are often moving, keeping a larger area in view, and often scanning the area around the human to make sure it isn't missing anything.
When it comes to numbers on human sight, it is difficult. Humans can have disabilities where they have issue seeing things far away. These numbers are assuming standard human vision. When on the ground, due to curvature, their distance sight is limited. On their home planet, they can see up to the horizon, which varies. For a 170cm tall human, the horizon would be 4.654 km away.
Assuming the human was on the 125th floor of the Burj Khalifa (tallest human building), they could see 76.03 km away.
The farthest a human could see without any assistance, and without a horizon, is the Andromeda Galaxy, approx. 2.5 million lightyears away. Impressive. It is blurry for their eyes, but they can see it.
This builds up to humans being a social, sight-based animal on eyes alone. Eyes are windows to the soul after all.
Imagine aliens find out that we have wrote songs about how you're going to die one day, have many proverbs about dying one day, write a lot of books about dying one day, and poems about dying one day.
Humans are quite strange in many ways. One of them is their rest cycle. Now, they aren't unusual for sleeping, but the way they sleep is very unique.
First of all, they almost never nap. Their sleep cycle is contained to the night, of 7-10 hours of sleep. Sleep schedules vary, but typically the earliest humans go to sleep is 8pm, and the latest they can wake up is 10am. Sometimes humans do attempt to nap, but their bodies treat it like a full rest.
Humans have two different ways they sleep, deep sleepers and light sleepers. Deep sleepers typically do not react to most stimuli when asleep, most concerningly sound can struggle to wake them up. However, they are more rested due to sleeping deep.
Light sleepers are the opposite. They are easily woken up, even by actions done while the human is asleep. They are alert when sleeping, but they wake up even when not necessary, and wake up less rested.
Either way, humans sleep concerningly deep. Lowered temperature, highly lowered brain function, and almost complete unawareness. However, they can move and speak while asleep. I have been reassured that the extreme version of this movement (Humans call this "Sleepwalking") is very rare, and only appears in children.
Humans also dream. Dreams are brain activity while the brain in question is asleep. From secondhand explanations, I have been told that typically it is a collage of recent memories. No one knows why.
Humans, are the only species to eat meat as a regular part of their diet and be classified as intelligent. Technically, humans are classified as omnivores, however humans eat plenty meat alongside plants.
Humans consume food through a large cavity in their head, with specialized bones coated with enamel in order to cut, crush and tear. The cavity itself is referred to as a mouth, and the specialized bones within are referred to as teeth, with the singular version being tooth. It is notable that these teeth are the main way of consuming things for mammals.
We can compare human teeth to other animals. Humans have canines, which are absent from herbivores. Canines is the term used for the for sharp teeth next to the incisors, and are used for tearing, only needed for meat eaters. Canines are most often found in mammalian predators. However, human molars, the large teeth in the back of the mouth used for crushing foodstuff, are notably more dull than carnivore teeth, but sharper than herbivores.
This duality shows that yes, humans do eat meat, but it shows that they are omnivores. Despite being classified as apex predators, meat is in no way absolutely necessary for the human diet. Attempts to convince humans to switch to an only plant based diet have mostly failed.
Another piece of evidence that points to humans being omnivores is that they have powerful acid in their stomach. This acidity allows for a wide range of things to be consumed, and for humans to eat some poisonous material, which is another story.