Help me compare these eyes to those eyes.
February 18, 2010 10:48 PM Subscribe
What animals/insects/etc have better vision than people?
I'm curious to know what animals, etc, have better vision than a person with 20/20 vision, and... as judged by a similar system where the animal's vision is the basis of 20/20 vision, what would the average person's vision be?
20/20 vision is basically what you see at 20 feet versus the distance the average person sees that same thing (more or less).
What about what a person sees at 20 feet versus the distance an eagle sees the same thing? What would the comparisons be? Would the person's vision be 20/200? 20/2000? And so on and so forth.
Is my question even answerable?
I'm curious to know what animals, etc, have better vision than a person with 20/20 vision, and... as judged by a similar system where the animal's vision is the basis of 20/20 vision, what would the average person's vision be?
20/20 vision is basically what you see at 20 feet versus the distance the average person sees that same thing (more or less).
What about what a person sees at 20 feet versus the distance an eagle sees the same thing? What would the comparisons be? Would the person's vision be 20/200? 20/2000? And so on and so forth.
Is my question even answerable?
Ah, take a look at this table on p.38 of Animal eyes.
posted by hattifattener at 11:14 PM on February 18, 2010 [1 favorite]
posted by hattifattener at 11:14 PM on February 18, 2010 [1 favorite]
Response by poster: OK... I didn't want to go here, but maybe I'll have to. Here's the real context for my question:
I'm legally blind. 20/200 to 20/250. Whenever I make a new friend, or especially if I start dating someone new, I will always eventually get the question "What can you see?" to which, I reply: "I don't know… what do you see?"
My vision hasn't changed. It isn't getting better or worse, so, I see what I've always seen and everything looks right to me. I can't compare what I see to normal vision because I've never had normal vision. And, really, I don't want to compare it because the last thing I want to do is go into embarrassing detail about how crappy my vision is.
This led me down the following thought path: my vision sucks compared to yours, but mine works well enough for me (for the most part. I do the best I can with what I've got). Your vision sucks in comparison to…? …but does that make your vision bad? Of course not. It just is what it is.
So… Compared to what animal/insect/fish/etc would a person with normal vision be blind?
posted by 2oh1 at 11:35 PM on February 18, 2010 [1 favorite]
I'm legally blind. 20/200 to 20/250. Whenever I make a new friend, or especially if I start dating someone new, I will always eventually get the question "What can you see?" to which, I reply: "I don't know… what do you see?"
My vision hasn't changed. It isn't getting better or worse, so, I see what I've always seen and everything looks right to me. I can't compare what I see to normal vision because I've never had normal vision. And, really, I don't want to compare it because the last thing I want to do is go into embarrassing detail about how crappy my vision is.
This led me down the following thought path: my vision sucks compared to yours, but mine works well enough for me (for the most part. I do the best I can with what I've got). Your vision sucks in comparison to…? …but does that make your vision bad? Of course not. It just is what it is.
So… Compared to what animal/insect/fish/etc would a person with normal vision be blind?
posted by 2oh1 at 11:35 PM on February 18, 2010 [1 favorite]
Hm. Well, if I'm interpreting that table correctly, a human actually has 20/40 eyesight compared to an eagle. Humans' vision seems to be at the acute end of the range; there aren't any animals whose vision is so much better that a baseline human would be blind in comparison.
Though, elsewhere I read that the eye is close to diffraction-limited, in which case you'd expect larger eyes to have better acuity (as well as better light gathering ability). That isn't really what that table shows, though, so perhaps I'm missing something.
Maybe night vision would be a good thing to compare against. Or maybe some other sense entirely (hearing?).
posted by hattifattener at 11:44 PM on February 18, 2010
Though, elsewhere I read that the eye is close to diffraction-limited, in which case you'd expect larger eyes to have better acuity (as well as better light gathering ability). That isn't really what that table shows, though, so perhaps I'm missing something.
Maybe night vision would be a good thing to compare against. Or maybe some other sense entirely (hearing?).
posted by hattifattener at 11:44 PM on February 18, 2010
Response by poster: Well shoot. I was under the impression eagles had some amazing vision in comparison to people. I guess I was hoping for an easy analogy that isn't there.
posted by 2oh1 at 11:48 PM on February 18, 2010
posted by 2oh1 at 11:48 PM on February 18, 2010
Some animals have vision that's just qualitatively different enough that it's not a one-to-one correspondence, too. Here's a bowhunting article about what deer see.
You may also want to read this article on visual acuity to see how the "20/20 is normal for humans" thing is not necessarily the case. Medical personnel attach numbers to these things for the sake of recordkeeping and reference; they're not intended as absolute descriptors even though folks with "normal" vision may use them as such when trying to understand the experience of the partially sighted/ legally blind/ other folks with visual issues.
I was born quite horribly nearsighted (and crosseyed) and have additional visual issues from retinal scarring and car-accident damage. The Snellen reference scale is never going to encompass the experience of my sight; generally, I just tell people "My glasses fix almost everything, but there are some issues they can't correct for. I work around those and get by fine, but I don't really have a reference point for what you see, so I can't really tell you relative to yourself-- I've been this way since I was an infant. Thanks for asking me, though."
posted by fairytale of los angeles at 11:58 PM on February 18, 2010 [1 favorite]
You may also want to read this article on visual acuity to see how the "20/20 is normal for humans" thing is not necessarily the case. Medical personnel attach numbers to these things for the sake of recordkeeping and reference; they're not intended as absolute descriptors even though folks with "normal" vision may use them as such when trying to understand the experience of the partially sighted/ legally blind/ other folks with visual issues.
I was born quite horribly nearsighted (and crosseyed) and have additional visual issues from retinal scarring and car-accident damage. The Snellen reference scale is never going to encompass the experience of my sight; generally, I just tell people "My glasses fix almost everything, but there are some issues they can't correct for. I work around those and get by fine, but I don't really have a reference point for what you see, so I can't really tell you relative to yourself-- I've been this way since I was an infant. Thanks for asking me, though."
posted by fairytale of los angeles at 11:58 PM on February 18, 2010 [1 favorite]
Humans (and some other great apes) have some of the best eyes in the animal kingdom.
A lot of people think that's because we evolved to be able to read facial expression in other apes, since social relationships are very important for Apes
And not only that, but Humans and closely related monkeys (plus some 'new world' monkeys) are the only animals with three color vision
posted by delmoi at 1:18 AM on February 19, 2010
A lot of people think that's because we evolved to be able to read facial expression in other apes, since social relationships are very important for Apes
And not only that, but Humans and closely related monkeys (plus some 'new world' monkeys) are the only animals with three color vision
posted by delmoi at 1:18 AM on February 19, 2010
2oh1, it may be that eagles, for instance, see great from a distance. Swoop in and kill, if prey still there.
I'm a visual artist and love to read, and I live in fear of losing my eyesight. Just for the record.
If your question is how to respond to your new dating person or friend, well, perhaps the best answer is to verbally describe what you see, if you're good with words and descriptions. If someone is interested, be eloquent. They care, or they wouldn't ask.
I have a friend who has a guide dog, but who used to draw charcoal pictures, but no longer can. We've had very interesting art talks. We had a candid "this is what the world looks like" conversation. He also likes to shoot big guns out at the family property in the woods.
My mom has had two retinal reattachment surgeries. As a commercial artist, she's found it easier to draw what she could for the eye docs, and that's been really helpful for her treatment. She's still working as a commercial artist because she could do this. If you have some vision and could share in this way, it might help your friends understand how the world looks to you.
I have yet another friend who is just plain blind, but wasn't always, and he was once married to a watercolor artist. He navigates with a cane and is a history major. His visual world is nothing but... nothing. He's older than me, and he can still describe her paintings. We talk art stuff and it's so interesting to get his perspective. I feel challenged to describe my work effectively and he gives a solid response.
So, what I'm getting at is that people talk to each other and can find a common ground. It's a challenge, sure. But I, for one, would be interested in hearing how you see the world, in your own words, not just some comparison. Your friends and potential girlfriends are probably interested, too.
posted by lilywing13 at 2:21 AM on February 19, 2010
I'm a visual artist and love to read, and I live in fear of losing my eyesight. Just for the record.
If your question is how to respond to your new dating person or friend, well, perhaps the best answer is to verbally describe what you see, if you're good with words and descriptions. If someone is interested, be eloquent. They care, or they wouldn't ask.
I have a friend who has a guide dog, but who used to draw charcoal pictures, but no longer can. We've had very interesting art talks. We had a candid "this is what the world looks like" conversation. He also likes to shoot big guns out at the family property in the woods.
My mom has had two retinal reattachment surgeries. As a commercial artist, she's found it easier to draw what she could for the eye docs, and that's been really helpful for her treatment. She's still working as a commercial artist because she could do this. If you have some vision and could share in this way, it might help your friends understand how the world looks to you.
I have yet another friend who is just plain blind, but wasn't always, and he was once married to a watercolor artist. He navigates with a cane and is a history major. His visual world is nothing but... nothing. He's older than me, and he can still describe her paintings. We talk art stuff and it's so interesting to get his perspective. I feel challenged to describe my work effectively and he gives a solid response.
So, what I'm getting at is that people talk to each other and can find a common ground. It's a challenge, sure. But I, for one, would be interested in hearing how you see the world, in your own words, not just some comparison. Your friends and potential girlfriends are probably interested, too.
posted by lilywing13 at 2:21 AM on February 19, 2010
Several years ago I went on a Visual Awareness course organised by the Royal National Institute for the Blind in the UK. This one. It is designed mainly for employees of organisations who are designing for or catering for people with visual impairments - but something like this would also be a great suggestion for somebody who wanted to have a concrete idea of what visual impairments of various kinds were like.
We were given various pairs of glasses which simulated tunnel vision, diabetic retinopathy, etc. One of the parts of the course I remember most vividly was the experience of being guided round the (unknown to me) training building while wearing one of these pairs of glasses.
Since human vision is quite good compared to other animals it might be easiest to compare it with other senses. For example a dog has about 30 times more cells devoted to processing smell than do humans. So on a smell scale a dog should be able to smell what we can detect at 20 feet from a distance of 600 feet: their smell is 600/20.
posted by rongorongo at 5:09 AM on February 19, 2010
We were given various pairs of glasses which simulated tunnel vision, diabetic retinopathy, etc. One of the parts of the course I remember most vividly was the experience of being guided round the (unknown to me) training building while wearing one of these pairs of glasses.
Since human vision is quite good compared to other animals it might be easiest to compare it with other senses. For example a dog has about 30 times more cells devoted to processing smell than do humans. So on a smell scale a dog should be able to smell what we can detect at 20 feet from a distance of 600 feet: their smell is 600/20.
posted by rongorongo at 5:09 AM on February 19, 2010
Also remember, some animals do see better than humans in different lighting conditions.
posted by Atreides at 6:25 AM on February 19, 2010
posted by Atreides at 6:25 AM on February 19, 2010
Response by poster: "If your question is how to respond to your new dating person or friend"
My question definitely isn't that. I thought an easy analogy could be made about an animal with better vision, but I'm wrong.
posted by 2oh1 at 9:33 AM on February 19, 2010
My question definitely isn't that. I thought an easy analogy could be made about an animal with better vision, but I'm wrong.
posted by 2oh1 at 9:33 AM on February 19, 2010
Maybe your analogy could be between human night vision and cat night vision? Cats see much, much better than we do in near-darkness, because their pupils are bigger, and thus let in more light. A human with average vision will be near-blind on a dark night, but a cat can see more-or-less normally. There's an article about it here.
posted by vorfeed at 11:51 AM on February 19, 2010
posted by vorfeed at 11:51 AM on February 19, 2010
This thread is closed to new comments.
Eyesight can be "better" in a lot of other ways as well (low-light vision; color vision (tetra- and higher chromaticity); ability to see fast things; weird stuff like polarization sensitivity (mantis shrimp!)).
posted by hattifattener at 11:06 PM on February 18, 2010