#monocular vision

Hello!

Unless there's a situation where they do only have one eye at the time and you're specifically referring to that for some reason, it's best to stick with "eyes".

A prosthetic eye is still an eye, just not in the same way.

Something else to consider is that messing with common phrases in an attempt to better include disability (for example, saying a character in a wheelchair "went for a roll" instead of "went for a walk") usually just makes the writing clunkier and harder to understand.

It's something I see a lot (particularly in fanfiction) and I always cringe little bit when I do.

In general, I'd suggest just keeping it as it is ("their eyes landed on X") or, if you really don't want to, use another expression (ex: "he looked at X", "their eyes met", etc.).

Cheers,

Monocular Vision

Hope this post helps.

here is a video that breaks down how monocular and binocular visions fields work:

and here is an image showing how the location of the eyes can change the way the vision field works:

(image description: two diagrams showing the visions fields for a cat and a horse. the cat has a wide triangle of binocular vision where both of its eyes can overlap their view, while the horse has much wider ranges for each eye but a very small overlap between the two eyes. end description.)

Having one eye like a cyclops or being a two eyed creature missing one eye for some reason would only produce a monocular vision field, which lacks a lot of depth perception. monocular vision can only see things from one angle at a time, so it's harder to compare how far away things are, or how big around something might be. it's not impossible to perceive depth with only one eye though! if you test it yourself by closing one eye, you'll notice how much smaller your field of view is without the extra peripheral, but you probably won't have too much trouble judging the distance and location of things in your immediate area, though it might be harder in an unfamiliar location. The farther away something is, the more difficult it will be for monocular vision to judge that distance.

a lot of herbivores rely on monocular vision. they have two eyes, but only a small overlapping area between their vision fields, so for the most part they have two separate monocular vision fields. they prioritize being able to see as wide a field as possible and reacting to unusual shapes and movements.

many predatory animals rely on having more effective binocular vision, having better depth perception with a narrower field of view. it's a more precise way to see, very good for detecting and keeping track of motion, judging distances, etc. you can see objects from two angles at once, giving a better sense of how big they are and where exactly they're located.

so how would trinocular vision work? would it have any extra advantages? Well, it's hard to say if it would be an advantage or not, since different methods of vision serve different purposes. but adding a third eye to something like a cat would certainly alter its vision field, and it might be more useful for such a predatory creature. it would, at the very least, provide one more angle of view. seeing things from one slightly higher angle than the two other eyes. not drastically different, just a slight change. it's hard to draw fully 3d vision fields in a way that fully illustrates how they overlap on every angle, but i have done my best to show the trinocular vision field here.

(image description: a simple sketch of a cat with a third eye on its forehead. in front of each eye is a colored field like a slice out of a circle, showing where each eye's vision overlaps with the others. it does not look much different from the binocular vision field, having a wide range of overlap in front of the face. end description.)

I wasn't sure how wide to go with the center eye's vision. how much would the placement restrict its peripheral? does it have an equally wide, more narrow, or more wide field of vision compared to the other eyes? those are all questions I think you'd have to answer for yourself if you're creating a trinocular creature. the wider the field of vision is for the third eye, the more it overlaps with the other eyes. this would make the binocular vision fields much wider on each side, essentially giving the creature more precise side vision and then creating a triple layer of vision in the middle. whether this is more helpful or more confusing is up to you I guess! like having two regular screens on each side of your head and then a 3d screen in the very front. I imagine the third eye might have a broader range of peripheral vision above the head.

EDIT: May tag as writing or reference for those who’ve asked, I love having more disabled rep! That said pls also check the notes to get an idea of how different experiences can be and more info, thank you <3

1. You only ever sit on one side of a room. (Especially if you’re in class) If you’re blind in your left eye like me, you sit to the left of the room so your right eye has the greatest scope, and there’s not much to your left to look at.

2. Harder time seeing past obstacles. People with two eye vision have the perception of both their eyes blend together for one image. Without this, you only have one eye, so you’re don’t get to see past obstacles the same way. For example if something is blocked for your right eye and not for your left, you can still see it through your left. For people with monocular vision this isn’t possible.

3. People don’t walk on the side of your blind eye. It may just be me, but because I’m blind in my left eye I tend to accidentally bump into people if they’re on my left. So when people walk beside me I naturally go so they’re to my right, or they do, without it being discussed.

4. 3D movies are headaches. Even though we’ve progressed past the red-blue type glasses, 3D just doesn’t work well for monocular vision. (And you know those fun optical illusions? A lot of them don’t work at all- nothing happens!)

5. Things like grabbing a pencil without looking at it are extremely difficult. (Due to lack of depth perception, you have a hard time discerning where things are in 3D space). This also stretches to having bad posture and balance. Meanwhile, things that are flat are relatively easy.

6. You turn your head when you’re looking at something, so your good eye is focused on it. This includes tilting your head at worksheets, TVs, and computer screens- and also people.

7. Seeing in the dark is also much harder, because people rely on their depth perception for it, and without that stuff gets real hard

8. The headaches. Most people with blindness don’t experience total blindness, but instead low vision, where their vision is not able to be used in a way that’s helpful. Your brain tries to merge the images, or use your bad eye to see something in the peripheral. This just makes your head hurt. Much like people who need time to adjust to having glasses due to the headache, getting headaches is common because your vision is always at odds.

9. More susceptible to eye damage. Since you’re not overly aware of your bad eye, you may not notice if the sun is shining directly at it. I tend to squint with my bad eye whenever I’m outside, without thinking about it. Additionally, you’re more wary of anything that could damage your good eye. It’s the only one, so you gotta be careful with it.

10. Also, it makes things really, really weird if there’s a bright light from one side but not from another. There are often after images that float in my vision.

11. Looking at things that are moving can be hard. I can focus on an object, but if a camera is panning in some direction without being focused on one thing in particular, I just stop being able to make sense of what I’m seeing. It becomes very jarring.

Kuroda seems to have a general good sense of smell.

Iori Muga however is finally revealing something I have suspected for so long... an indication to having monocular vision (prosthetic eye). This old habit of turning his head often is very common for people who adjusted to having monocular vision (seeing through one eye) in order to compensate for their worsened peripheral vision. This was the final piece to completing all the Rum hints for Muga (having a prosthetic eye).

Gosho overtly showing this suspicious trait in Muga through 4 panels (File 1089) is a good sign to that he is not shying away from portraying Muga as extra suspicious anymore, after revealing Rum to be disguised as Wakita, so I'm very excited to see what other obvious hints Gosho is gonna reveal that hints to Muga being Rum's true identity.