4 ms·

> we can’t read out of the corner of our eyes, no matter how hard we try This is not quite true. Reading via peripheral vision is a skill, but most people neve

by pxc 2y ago

> we can’t read out of the corner of our eyes, no matter how hard we try This is not quite true. Reading via peripheral vision is a skill, but most people never have the right kind of motivation (and perhaps not the right kind of visual stimulus) to learn it. I know this because I have personally known someone who read exclusively via her peripheral vision. There's an inherited retinal disease that runs in my family. It's a form of 'cone-rod dystrophy'. Cone-rod dystrophies are diseases where the cones and the rods in the eye eventually stop responding to light. The order of the terms in the naming reflects the typical order of the dystrophy: first the cones (responsible for central vision) go, then the rods (responsible for peripheral vision) go, too. As the cones and rods go bad, this results in loss of visual acuity in central and peripheral vision respectively. (It often causes lots of other, less generic problems, too, such as: blind spots, warping/twisting distortions in the visual field, sometimes flickering artifacts, progressive colorblindness, extreme light sensitivity, and an effective reduction of contrast.) Between individual cases, there's a lot of variation in how the disease presents. There's no fixed timeline or ordering for the progression (even though the disease's genetic cause has been identified as just a single gene!). Anyhow, in my late aunt's case, her central vision was useless long before her peripheral vision could give out. So she learned, somehow, to do things like read her smartphone using only her peripheral vision. We chatted about it once or twice. Onlookers often could not comprehend that she was looking at her phone, since her eyes weren't pointed towards it. She once laughed to me about how someone had asked her 'Why are you sniffing your phone?', while she held it up to her face to read a text message. My impression is that learning to rely on your peripheral vision in this way is extremely counter-intuitive and difficult to do. (This may have something to do with the mechanisms discussed in TFA.) I wonder if it can even be done at all without first obscuring one's central vision (which I guess you could do artificially with contacts). But evidently it can be done.

GuB-42 2y ago
It makes me think of a common trick in stargazing that is to look at stars with peripheral vision. Fixating them will make them disappear. That's because the fovea, the "high resolution" part of the eye we use when focusing on some point is entirely made of cone cells, which give you color vision, but are less sensitive, as opposed to rod cells, that make up most of the peripheral vision. In other words, peripheral vision is better in low light situations.
- axwdev 2y ago
  I discovered this growing up when lying in bed at night. I'd always feel like there was light coming under the door. Then I'd look directly at it and it was pitch black to me. I'd look to the side and the light would seemingly come back. Only years later did I discover the cause you described.
  - fluoridation 2y ago
    I discovered it similarly in a camping trip when I was a kid. We were walking around in near pitch darkness, and I saw out of the corner of my eye someone walk away from the group and try to hide behind a table or something. When I turned to look I couldn't see anything at all, but if I averted my eyes I could clearly see there was a person moving around crouched behind a table. I can't remember exactly, but I think I wasn't so much seeing them, but rather their movement, and mentally perceiving their silhouette. I guess it looks sort of like this: https://www.youtube.com/watch?v=M83sF7_fYdM https://www.youtube.com/watch?v=M83sF7_fYdM
    - xerox13ster 2y ago
      This was used as a magical trait in Tamora Pierce's Circle of Magic books. One of the characters has the ability to see magic and beings at the edge of her vision ("around" her glasses).
- intelVISA 2y ago
  You can also discern some flickering lights in your periphery that are otherwise 'solid' when focused on. Quite annoying.
fluoridation 2y ago
I guess what the article means is that it's not possible to read with peripheral vision except with very large font size and up close. Was your aunt able to read normal print besides titles? Also, I just tried out of curiosity. I must imagine only her fovea was unusable, and the area just around it (I think it's like 5° off-axis) was still fine, because I think I have pretty good peripheral vision, and I can't make out anything if I intentionally look away from what I'm trying to read. Certainly not on a phone; I have to get it so close to my face that it goes out of focus. By the way, while it is true that cones are far more densely packed in the fovea, their function is color vision, not central vision. Rods are responsible for motion perception and vision in low-light environments.
- pxc 2y ago
  > except with very large font size and up close Yeah, it's hard to say what the determinative factors were because her general visual acuity was so low that she generally needed very large fonts very up close anyway. My mom and my sister and I also have this condition and rely on magnification to varying degrees (and for various reasons— sometimes it's truly about acuity but sometimes larger sizes/bolder fonts are a clumsy way to try to make up for contrast issues). But even those of us with usable central vision generally need large fonts anyway. We're also all, for reasons I think are mostly incidental, naturally myopic (although my mom is no longer nearsighted but farsighted (with low acuity— she's legally blind)). > Was your aunt able to read normal print besides titles? No. Even titles, like titles of chapters in a paperback, she could likely only read with magnification. And that's if she could get enough contrast at all. At some point, screens become much easier to read than paper, even at equal sizes. I should learn more about the precise anatomy because it's interesting, but currently I know more about the subjectivity of it than the mechanics. > By the way, while it is true that cones are far more densely packed in the fovea, their function is color vision, not central vision. Rods are responsible for motion perception and vision in low-light environments. There may be other factors in these inherited retinal dystrophies that affect the way their progressions affect field of view, idk. But what I said about which areas are first distorted for cone-rod dystrophies is true, and its reverse is true for rod-cone dystrophies (i.e., retinitis pigmentosa), where people with that condition lose their peripheral vision first and their field of view shrinks from the outside-in. My assumption so far has been that this corresponds to those density differences you mentioned. > Rods are responsible for motion perception and vision in low-light environments. I do know that much. :) One of the features of this illness that's very prevalent for me and my sister right now is extreme light sensitivity, presumably because our eyes rely increasingly on their rods even during the daytime and even in high-light environments. One related I've written about on HN before is how the need for lower total light emission pushes both of us to high-contrast dark themes with the lowest brightness possible. OLED screens are really nice when your rods are in better shape than your cones! One that I don't think I have is that my colorblindness has been getting worse over time. The last time I took a colorblindness test (administered by a medical professional, at my retinal specialist's office), I could hardly read any of the Ishihara plates at all. (When the doctor came in, he asked me if I only saw in black-and-white, which I found mildly irksome but very amusing. I laughed about it with my family afterwards. I do still see many colors! I just have trouble distinguishing a lot of them, too.) My sister, who was not colorblind at all when she was growing up, is now also colorblind, about as much as me based on her tests.
Daub 2y ago
> Anyhow, in my late aunt's case, her central vision was useless long before her peripheral vision could give out. So she learned, somehow, to do things like read her smartphone using only her peripheral vision. All I can say is wow.
- pxc 2y ago
  Humans are incredibly adaptable beings, and she proved it. :) She'd been through a hell of a lot in her life, but it was always important to her to be pleasant company to the people around her, even in tough times. She was always joking and laughing and telling stories. RIP
hinkley 2y ago
Macular degeneration also tends to start in the middle and spread outward. Those people learn the same tricks.
- pxc 2y ago
  Yep. Before my mom got a correct diagnosis via genetic testing, she was told it was a form of macular degeneration, in part on the basis of those features.

by pxc 2y ago

GuB-42 2y ago

It makes me think of a common trick in stargazing that is to look at stars with peripheral vision. Fixating them will make them disappear. That's because the fovea, the "high resolution" part of the eye we use when focusing on some point is entirely made of cone cells, which give you color vision, but are less sensitive, as opposed to rod cells, that make up most of the peripheral vision. In other words, peripheral vision is better in low light situations.

axwdev 2y ago
I discovered this growing up when lying in bed at night. I'd always feel like there was light coming under the door. Then I'd look directly at it and it was pitch black to me. I'd look to the side and the light would seemingly come back. Only years later did I discover the cause you described.
- fluoridation 2y ago
  I discovered it similarly in a camping trip when I was a kid. We were walking around in near pitch darkness, and I saw out of the corner of my eye someone walk away from the group and try to hide behind a table or something. When I turned to look I couldn't see anything at all, but if I averted my eyes I could clearly see there was a person moving around crouched behind a table. I can't remember exactly, but I think I wasn't so much seeing them, but rather their movement, and mentally perceiving their silhouette. I guess it looks sort of like this: https://www.youtube.com/watch?v=M83sF7_fYdM https://www.youtube.com/watch?v=M83sF7_fYdM
  - xerox13ster 2y ago
    This was used as a magical trait in Tamora Pierce's Circle of Magic books. One of the characters has the ability to see magic and beings at the edge of her vision ("around" her glasses).
intelVISA 2y ago
You can also discern some flickering lights in your periphery that are otherwise 'solid' when focused on. Quite annoying.

fluoridation 2y ago

I guess what the article means is that it's not possible to read with peripheral vision except with very large font size and up close. Was your aunt able to read normal print besides titles? Also, I just tried out of curiosity. I must imagine only her fovea was unusable, and the area just around it (I think it's like 5° off-axis) was still fine, because I think I have pretty good peripheral vision, and I can't make out anything if I intentionally look away from what I'm trying to read. Certainly not on a phone; I have to get it so close to my face that it goes out of focus. By the way, while it is true that cones are far more densely packed in the fovea, their function is color vision, not central vision. Rods are responsible for motion perception and vision in low-light environments.

pxc 2y ago
> except with very large font size and up close Yeah, it's hard to say what the determinative factors were because her general visual acuity was so low that she generally needed very large fonts very up close anyway. My mom and my sister and I also have this condition and rely on magnification to varying degrees (and for various reasons— sometimes it's truly about acuity but sometimes larger sizes/bolder fonts are a clumsy way to try to make up for contrast issues). But even those of us with usable central vision generally need large fonts anyway. We're also all, for reasons I think are mostly incidental, naturally myopic (although my mom is no longer nearsighted but farsighted (with low acuity— she's legally blind)). > Was your aunt able to read normal print besides titles? No. Even titles, like titles of chapters in a paperback, she could likely only read with magnification. And that's if she could get enough contrast at all. At some point, screens become much easier to read than paper, even at equal sizes. I should learn more about the precise anatomy because it's interesting, but currently I know more about the subjectivity of it than the mechanics. > By the way, while it is true that cones are far more densely packed in the fovea, their function is color vision, not central vision. Rods are responsible for motion perception and vision in low-light environments. There may be other factors in these inherited retinal dystrophies that affect the way their progressions affect field of view, idk. But what I said about which areas are first distorted for cone-rod dystrophies is true, and its reverse is true for rod-cone dystrophies (i.e., retinitis pigmentosa), where people with that condition lose their peripheral vision first and their field of view shrinks from the outside-in. My assumption so far has been that this corresponds to those density differences you mentioned. > Rods are responsible for motion perception and vision in low-light environments. I do know that much. :) One of the features of this illness that's very prevalent for me and my sister right now is extreme light sensitivity, presumably because our eyes rely increasingly on their rods even during the daytime and even in high-light environments. One related I've written about on HN before is how the need for lower total light emission pushes both of us to high-contrast dark themes with the lowest brightness possible. OLED screens are really nice when your rods are in better shape than your cones! One that I don't think I have is that my colorblindness has been getting worse over time. The last time I took a colorblindness test (administered by a medical professional, at my retinal specialist's office), I could hardly read any of the Ishihara plates at all. (When the doctor came in, he asked me if I only saw in black-and-white, which I found mildly irksome but very amusing. I laughed about it with my family afterwards. I do still see many colors! I just have trouble distinguishing a lot of them, too.) My sister, who was not colorblind at all when she was growing up, is now also colorblind, about as much as me based on her tests.

Daub 2y ago

> Anyhow, in my late aunt's case, her central vision was useless long before her peripheral vision could give out. So she learned, somehow, to do things like read her smartphone using only her peripheral vision. All I can say is wow.

pxc 2y ago
Humans are incredibly adaptable beings, and she proved it. :) She'd been through a hell of a lot in her life, but it was always important to her to be pleasant company to the people around her, even in tough times. She was always joking and laughing and telling stories. RIP

hinkley 2y ago

Macular degeneration also tends to start in the middle and spread outward. Those people learn the same tricks.

pxc 2y ago
Yep. Before my mom got a correct diagnosis via genetic testing, she was told it was a form of macular degeneration, in part on the basis of those features.