4 ms·

I unfortunately know more than I would like about dog eyes, because my 4 year old GSD had cataracts. Some of the differences the vet told me are interesting.

I unfortunately know more than I would like about dog eyes, because my 4 year old GSD had cataracts. Some of the differences the vet told me are interesting. Dogs vision is about 20/200 in general, and they can only use their lens to focus 1-2 diopters (compared to about 6 for people). Dogs can track movement and see in low light better than we can. The way that he did an eye test was simply to drop a cotton ball, the difference before surgery and 2 days after surgery was stark. He would ignore it before, and afterwards his head followed it.

luckylion 6y ago
> Dogs can track movement and see in low light better than we can. This goes against my experience. When I was dog sitting my mother's dog a few years ago and we were going for the final walk of the night, she'd regularly get surprised by people passing us from the opposite direction. She'd notice them 1-2 meters away and would jump back and bark, while I was easily able to see them 5-10m away. I've had similar experiences with another dog. Would they notice them better if they were moving side to side instead of slowly becoming bigger while walking towards us?
- deleted 6y ago
  [deleted]
- archi42 6y ago
  Difficult to judge: Better sight doesn't mean "better human-like sight". Maybe dogs are better at seeing fast moving gradients (e.g. when racing prey), but have difficulties with slow changes (e.g. predator slowly closing in). Also, maybe the dogs just assumed that /you/ would be looking out for any "enemies", and were then just surprised because you didn't warn them about the impeding "attack" while they had other things in mind ;-)
- technothrasher 6y ago
  I notice when I take my pup out to pee in the early morning that I'm much better at spotting wildlife than she is. We live in a pretty wooded area, so there are plenty of animals about. A deer staring at us, an owl looking down, a stray coyote heading home after a night's prowl, a fisher slinking back to the swamp... she won't notice any of them unless they're either very close, make a lot of noise, or if she can smell their trail. When she does notice them she gets very interested, so I don't think it's her not caring. It may well just be my higher line of sight.
- fingerlocks 6y ago
  Did your mother's dog have reflective eyeballs? If so, that's called a Tapetum Lucidum[0], and most dogs breeds have it. It's what make animals' eyes appear to glow in the dark. Light reflects off the back of the eye so the retina can absorb more of it, allowing for improved vision at night. [0]https://en.wikipedia.org/wiki/Tapetum_lucidum https://en.wikipedia.org/wiki/Tapetum_lucidum
buserror 6y ago
I use that fact quite a bit when training my labrador; when in the woods, if she ranges too far, I'll just stop and stay completely motionless. She'll fail to see me at about 15-20 meters from me, especially if I'm against a tree or something. Even if I'm not obscured at all. Soon tho, her nose will pick me and I can then see her eyes 'click' on me eventually. I use that trick to keep her "worried" she'll lose me, so she keeps checking on me at shorter intervals and control her urge to follow a yummy smell. The interesting thing is that on the other hand, she has no problem tracking a moving object in flight at 100m, like a pigeon. Once I was shooting clay pigeons, and missed one overhead, and a few minutes later she came back all happy with my unbroken clay target, she had tracked it, marked it, and retreived it!
- pmiller2 6y ago
  Your comment about fetching led me to remember a Reddit post from the other day, where a dog (apparently also a Labrador or Lab mix) was able to fetch a single wood chip tossed a few meters away: https://www.reddit.com/r/videos/comments/h8dkjv/yogi_got_a_lot_of_haters_yesterday_saying_his/ https://www.reddit.com/r/videos/comments/h8dkjv/yogi_got_a_l...
rckoepke 6y ago
> Dogs vision is about 20/200 in general I'd be careful with this one. I thought the same when I got a puppy, I'd heard similar repeated (often 20/75 is mentioned as well), and especially that they're not supposed to see well in the dark. After his adolescence my Texas Heeler seems to have excellent vision. He regularly spots small birds, piglets, humans, etc at a distance of 1/4 mile through our window (that's as far as the view goes, but many of the objects he sees rival in size what a human can see at a similar distance). Nighttime does not seem to effect this much. I'm sure his vision is at least 20/40, probably even better than 20/30. He also seems to have more aggressive pattern recognition through partially obscured sightlines. e.g. seeing a deer or human from just a tiny visual sample viewable through dense trees/brush. However, while this seems to have higher sensitivity than humans (sees the deer when humans dont) it also seems to have somewhat lower specificity (occasionally he thinks something is there when it really isn't). While this could be due to some Dingo genetics not found in other dogs (unique to Australian Cattle Dogs), it's worth noting that Icelandic Sheepdogs were bred partly to defend unusually small icelandic sheep/goats from unusually large birds of prey that eat them (the white-tailed eagle). Therefore they bark at everything that flies, and some owners have noted that they sometimes bark at birds or airplanes that are quite difficult for humans to see. My personal hypothesis is that there is wider individual variation in canine sight acuity than is acknowledged by the typical rules of thumb.

luckylion 6y ago

> Dogs can track movement and see in low light better than we can. This goes against my experience. When I was dog sitting my mother's dog a few years ago and we were going for the final walk of the night, she'd regularly get surprised by people passing us from the opposite direction. She'd notice them 1-2 meters away and would jump back and bark, while I was easily able to see them 5-10m away. I've had similar experiences with another dog. Would they notice them better if they were moving side to side instead of slowly becoming bigger while walking towards us?

deleted 6y ago
[deleted]
archi42 6y ago
Difficult to judge: Better sight doesn't mean "better human-like sight". Maybe dogs are better at seeing fast moving gradients (e.g. when racing prey), but have difficulties with slow changes (e.g. predator slowly closing in). Also, maybe the dogs just assumed that /you/ would be looking out for any "enemies", and were then just surprised because you didn't warn them about the impeding "attack" while they had other things in mind ;-)
technothrasher 6y ago
I notice when I take my pup out to pee in the early morning that I'm much better at spotting wildlife than she is. We live in a pretty wooded area, so there are plenty of animals about. A deer staring at us, an owl looking down, a stray coyote heading home after a night's prowl, a fisher slinking back to the swamp... she won't notice any of them unless they're either very close, make a lot of noise, or if she can smell their trail. When she does notice them she gets very interested, so I don't think it's her not caring. It may well just be my higher line of sight.
fingerlocks 6y ago
Did your mother's dog have reflective eyeballs? If so, that's called a Tapetum Lucidum[0], and most dogs breeds have it. It's what make animals' eyes appear to glow in the dark. Light reflects off the back of the eye so the retina can absorb more of it, allowing for improved vision at night. [0]https://en.wikipedia.org/wiki/Tapetum_lucidum https://en.wikipedia.org/wiki/Tapetum_lucidum

buserror 6y ago

I use that fact quite a bit when training my labrador; when in the woods, if she ranges too far, I'll just stop and stay completely motionless. She'll fail to see me at about 15-20 meters from me, especially if I'm against a tree or something. Even if I'm not obscured at all. Soon tho, her nose will pick me and I can then see her eyes 'click' on me eventually. I use that trick to keep her "worried" she'll lose me, so she keeps checking on me at shorter intervals and control her urge to follow a yummy smell. The interesting thing is that on the other hand, she has no problem tracking a moving object in flight at 100m, like a pigeon. Once I was shooting clay pigeons, and missed one overhead, and a few minutes later she came back all happy with my unbroken clay target, she had tracked it, marked it, and retreived it!

pmiller2 6y ago
Your comment about fetching led me to remember a Reddit post from the other day, where a dog (apparently also a Labrador or Lab mix) was able to fetch a single wood chip tossed a few meters away: https://www.reddit.com/r/videos/comments/h8dkjv/yogi_got_a_lot_of_haters_yesterday_saying_his/ https://www.reddit.com/r/videos/comments/h8dkjv/yogi_got_a_l...

rckoepke 6y ago

> Dogs vision is about 20/200 in general I'd be careful with this one. I thought the same when I got a puppy, I'd heard similar repeated (often 20/75 is mentioned as well), and especially that they're not supposed to see well in the dark. After his adolescence my Texas Heeler seems to have excellent vision. He regularly spots small birds, piglets, humans, etc at a distance of 1/4 mile through our window (that's as far as the view goes, but many of the objects he sees rival in size what a human can see at a similar distance). Nighttime does not seem to effect this much. I'm sure his vision is at least 20/40, probably even better than 20/30. He also seems to have more aggressive pattern recognition through partially obscured sightlines. e.g. seeing a deer or human from just a tiny visual sample viewable through dense trees/brush. However, while this seems to have higher sensitivity than humans (sees the deer when humans dont) it also seems to have somewhat lower specificity (occasionally he thinks something is there when it really isn't). While this could be due to some Dingo genetics not found in other dogs (unique to Australian Cattle Dogs), it's worth noting that Icelandic Sheepdogs were bred partly to defend unusually small icelandic sheep/goats from unusually large birds of prey that eat them (the white-tailed eagle). Therefore they bark at everything that flies, and some owners have noted that they sometimes bark at birds or airplanes that are quite difficult for humans to see. My personal hypothesis is that there is wider individual variation in canine sight acuity than is acknowledged by the typical rules of thumb.