Eye - appearance and function (for my scifi)

[Destructionator XV]

Earlier today I made the observation that most animal's white part of their eyes aren't easily visible all the time. For example, imagine a dog's eyes. They appear to be colored through almost all the visible part; the white parts are only off to the side. All other mammals and even birds (well, the hunters at least) I can think of follow a similar pattern.

So, figuring that humans are the weirdo of the animal kingdom here, I decided to say my aliens follow in the more common pattern and have dog like eyes.

However, someone just now said that the different appearance might show different function - different ability to focus on objects, perhaps different ability to pick up color. I'm not sure about this, which is what brings me here.

Does having eyes that look like non human animals necessarily imply any different function, or is the human look just a random species identifier (or something) that has no impact of function?

[frigidmagi]

I think it has no impact. I mean there are lot of bird species that see in color and focus better then we do and the whites of their eyes aren't noticeable.

[The Village Idiot]

We cannot acuratly compare the differences in eyes and eye function due to the whole sentiance issue. But the concencus at the hospital is: The Iris does not nessisarly dictate the ability to see, the Pupal, Cornea, and Retna. The Pupal, of course, manages the amount of light let into the eye. The Cornea focus that light onto the Retna(various parts of the retna, like rods and cones, pickup various parts of that light) which then sends signals through the Optic Nerve to the brain to be interpreted into what is "Seen". So... whats my point?

How the eye looks doesnt nessisarly dictate function, eye construction and to an extent brain function does. Think the funny shape but greater ability to see (at least in some aspects, we can't totally determine for various testing reasons.) in cats eyes, or birds eyes over humans.

[B4UTRUST]

While we can't verify it, it's fairly well established that amongst the sight-dependent animals we're pretty bad. Most of them have better distance and focusing as well as night vision then we do. What this has to do with the whites of the eyes I have no the slighest or any clue if actually makes a difference other then helping them blend in (easier to see a bright speck of white at night then muted shades of yellow or only hints of white).

[Comrade Tortoise]

Earlier today I made the observation that most animal's white part of their eyes aren't easily visible all the time. For example, imagine a dog's eyes. They appear to be colored through almost all the visible part; the white parts are only off to the side. All other mammals and even birds (well, the hunters at least) I can think of follow a similar pattern.

So, figuring that humans are the weirdo of the animal kingdom here, I decided to say my aliens follow in the more common pattern and have dog like eyes.

However, someone just now said that the different appearance might show different function - different ability to focus on objects, perhaps different ability to pick up color. I'm not sure about this, which is what brings me here.

Does having eyes that look like non human animals necessarily imply any different function, or is the human look just a random species identifier (or something) that has no impact of function?

Actually, it is very functional. We use our eyes for signaling other individuals. This would be very difficult without some sort of contrast. Have you ever signaled someone with your eyes? I have.

You can use it for both honest signaling and deception. An example of this is clearly signaling sexual interest in a female with your eyes, to her, while duping her partner by keeping your actual head straight forward.

There are lots of other applications as well, all have to do with communication. You will want a sapient species with that kind of high-contrast eye. Unless you want them to be easily duped by species that do have that method of signaling.

[Destructionator XV]

There are lots of other applications as well, all have to do with communication. You will want a sapient species with that kind of high-contrast eye. Unless you want them to be easily duped by species that do have that method of signaling.

I think I do want that - communication between them and humans isn't the cleanest process. Edit: a quick clarification: I like the idea of communication with humans not being easy. I in real life have a hard enough time figuring out humans myself, and I'm one of you who lives here, so it seems to me that it shouldn't be even remotely easy from someone from another planet to understand it all. /edit

It basically comes in three stages (usually repeated for each individual as he learns for himself):

1) complete obliviousness to the human's intention and utter ignorance in basic communication back to him. They essentially talk past each other.

2) Trying too hard to emulate human behaviour and ending up overdoing it or emulating something incorrectly. He might observe human signals, but still doesn't really understand what they mean.

3) Finally figuring it out. He still doesn't intuitively understand humans nor naturally communicate in their manner, but he has learned to emulate and understand it as best he physically can.

By the time someone gets to step #3, for the eye thing specifically, this means he has learned to watch human eye movements and may try to copy them himself, but this copying might not easily seen due to the poorer contrast.


So I think it fits in beautifully with how I want to protray the alien/human interaction. Now, since I try to keep to generally hard sci fi here, which includes not butchering evolution too badly (aside from the big handwave of an alien planet having an Earth like biosphere with generally humanoid inhabitants in the first place), so we'd want to think about how this lack of communication would change things among themselves.

I don't think it is a showstopper based on the simple observation that there are lots of social species in the real world that do fine like this. They can always signal in other ways; perhaps ear movements? I've already given them voluntarily flexible ears they use to signify things like attentiveness.


EDIT 2: And couldn't the poorer contrast also be a good thing for fooling someone? At quick look, it would be harder to see what they are looking at.

[Comrade Tortoise]

Yes, that is one benefit. An individual would not be able to dual-signal or give hidden signals with his eyes. But would also be more difficult to read as well. He could very intentionally mislead someone if he wished because his eyes could not be read.

[LadyTevar]

I don't think it is a showstopper based on the simple observation that there are lots of social species in the real world that do fine like this. They can always signal in other ways; perhaps ear movements? I've already given them voluntarily flexible ears they use to signify things like attentiveness.

Wolves use ear movements, tail movements, and body posture to communicate within the pack.