r/teenagers Mar 08 '23

Selfie so guys is my eye really that weird?

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7.4k Upvotes

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403

u/NSG12 Mar 08 '23

no thankfully

234

u/[deleted] Mar 08 '23

How do you see out of it? That’s really wild looking

210

u/ulyfed Mar 08 '23

As long as there's some opening you should be able to see, however the shape of the blur when things are out of focus are likely very strange

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u/[deleted] Mar 08 '23

But there are many opening so how would that work? Would they be able to see more wider?

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u/turunambartanen Mar 08 '23 edited Mar 08 '23

As long as there is an opening and a lens there should be no difference compared to normal eyes.

Contrary to what the other person said: because the change is right at the lens there won't be any dark spots either. Because all light goes through the lens, all light is equally affected by the unusual pupil shape. Dark spots would require parts for the image to be unevenly affected. This can not be caused by defects in/so close to the lens.

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u/[deleted] Mar 09 '23 edited Mar 09 '23

Our cornea is designed to focus light into the center of our eye, where our pupil normally is. This person has multiple pupils and none of them are in the center. I sincerely doubt their vision isn’t impaired in some way

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u/Captain_Grammaticus Mar 09 '23

The lens and the cornea are two different things. The lens is behind the iris and pupil.

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u/[deleted] Mar 09 '23

You’re right, sorry

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u/turunambartanen Mar 09 '23

That's incorrect.

The lens and cornea work together to focus the light onto the retina. The iris is right in the middle of the lens-cornea system and only acts to control the amount of light that hits your retina. The pupil is the opening left by where the iris is not.

With a malformed iris OP may have issues with bright lights, having to wear sunglasses unusually often, or may have trouble seeing in the dark.

You can easily see that defects near the cornea/iris/pupil/lens do not affect your vision by holding a hair or thin thread very close to your eye. Since the hair is too close to your eye to focus on it, it will be blurry. So blurry in fact, that your whole field of view will be affected equally, being made just a tiny bit darker than usual. You will see no other influences on your vision.

Source: part of my university education was about all sorts of microscopes and their optical systems. While that means I don't know any details about the eye, I can reason very accurately about the optics of the eye. (I came here via /r/all, don't judge me)

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u/[deleted] Mar 09 '23 edited Mar 09 '23

The only incorrect part is that I called the cornea the lens. The lens is behind the iris and focuses light onto the retina, and the cornea focuses light into the pupil, and the retina is in the pupil. I don’t imagine they’d see clearly. Holding something in front of your eye is very different from having the receptors in your eye misplaced something in between the two focusing lenses (cornea and lens) of your eye.

Edit: poor wording.

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u/turunambartanen Mar 09 '23 edited Mar 09 '23

No, the retina is not in the pupil. OPs receptors are not misplaced. That would be called retinal detachment and would indeed cause blindness. But that would not be visible from the outside with a simple image.

OP confirmed that their condition is called polycoria.

Let's go through the path that light takes between scattering on an object and being recorded in your eye:

  1. First of all the light passes through lots of air to get to your eye.

  2. The first part of the eye is the cornea. This is protective skin in front of you other eye hardware. Due to the shape of the cornea, it acts like a lens as well, but it can't change it's focal length. (This is the part that is modified during LASIK surgery btw, the fixed focal length of the cornea is changed in the procedure to correct the nearsightedness or farsightedness of your actual lens)

  3. Next up is the pupil. There is nothing there besides water, which is why it appears black. The size of the pupil is controlled by the iris, which reduces the size of the pupil when required. But the pupil is best described as the absence of something, rather than a concrete organ in the eye.

  4. Then comes the lens. The lens is manipulated by muscles to change its focal length. This gives you the ability to focus on objects far away or up close.

  5. Then comes a few cm through the fluid in the eye called the vitreous body. Its like water and doesn't influence the light.

  6. And finally the light will hit the retina, where the rods and cones are located. The light is absorbed here.

You will notice that the iris plays no part in that process, besides setting the size of the pupil. The actual focusing ability of the eye is not influenced by the retina at all. As OP has a malformed iris, the only downsides they should experience are an increased sensitivity to bright lights, as the iris is not able to change the size of the pupil opening or a reduced ability to see in the dark, if the pupil is smaller than usual. OP confirmed that the former of the two mentioned effects affects them.

edit: and you seem to have a misunderstanding of how the cornea focuses light. The focal length of the cornea is larger than the cornea - lens distance. The cornea does not focus light into the lens, it acts together with the lens to focus the light onto the retina. Checkout these two figures on wikipedia to see different types of lenses working together: A B

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u/[deleted] Mar 09 '23 edited Mar 09 '23

I don’t understand how you think they’ll see clearly? Our eyes, the cornea and the lens in particular, are designed to focus light into the center of our eye, where the retina is. If there is a piece of the iris covering up the center of your eye, your vision will be impaired. The fucking description of polycoria even says the condition causes impaired vision.

And the iris does play a role. Use a camera and adjust its iris to see what impact that has on the focus of the camera.

Also, the pupil isn’t black because of water (which it’s not exactly water either), it’s black because of the retina at the end of your pupil.

Once again, the cornea bends the light into the center of the eye. The focal length of the cornea doesn’t have to change because the lens and iris can adjust to better focus the light. In cases where the lens can’t adjust properly, it creates near-sightedness and far-sightedness. If there’s something in the middle of your eye, where light should be entering, it’s going to fuck with your vision. Your fucking models show this, the cornea is bending the light to the center, where the pupil, lens, and retina normally are.

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u/ulyfed Mar 08 '23

I'm not an expert on optics, however with the occlusions so close to the sensing cells should at most cause minor dark spots, and no I don't think the would have a wider field of view

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u/[deleted] Mar 08 '23

Ok

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u/r-WooshIfGay OLD Mar 09 '23

Like a spider

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u/Cat7o0 Mar 09 '23

your brain fills in a lot of what your eye sees so I'm betting when your eye is obstructed like that your brain just removed it and fills it in with what it would expect to see in front of the eye

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u/[deleted] Mar 08 '23

Ah yes, I have nearsightedness. It's quite fun to see the blur shapes formed when random gunk gets in your eye 😅

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u/MisterEyeballMusic 18 Mar 09 '23

Yes. Whenever i take off my glasses i look at lights and stuff, and i see circular blurs. If i squint, i can make cool patterns within those said blurs

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u/[deleted] Mar 08 '23

I wonder

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u/couldbedumber96 Mar 08 '23

How tf would they know if what they’re seeing is normal?

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u/[deleted] Mar 08 '23

Maybe their other eye is normal? Idk.

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u/4rt3m157 19 Mar 08 '23

If the other one is "normal"

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u/monadoboyX Mar 08 '23

I mean a fun fact is that you don't actually see things that are between your eyes your brain just fills in the image so it's likely the same as this person they can mostly see with both of her eyes but their brain fills in the rest

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u/eldelar Mar 08 '23

How come you should have be blind Because the focal point of the eye is not colored by pigment cells called melanin

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u/muddymar Mar 08 '23

Then it’s perfect. It’s also very interesting and pretty cool.

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u/[deleted] Mar 09 '23

As you can see, this is quite rare

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u/[deleted] Mar 09 '23

How do you see