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Tom Mazanec
2017-Sep-23, 02:33 PM
Do slit pupils make it easier for animals to see things oriented with the pupil, like vertical things for a cat or horizontal things for a mongoose?

01101001
2017-Sep-23, 03:07 PM
it makes the distance of their prey easier for cats to judge with stereo vision.

The Web knows: https://www.livescience.com/51787-why-cats-have-vertical-pupils.html

swampyankee
2017-Sep-23, 03:25 PM
I have also read the slit pupils permit greater light-gathering area at night and good vision in bright sun light.

WaxRubiks
2017-Sep-23, 03:25 PM
Goats have funny eyes too:

http://hencam.com/static/uploads/2013/01/rectangular-eye.jpg

Noclevername
2017-Sep-23, 03:37 PM
My sister went to college with a girl who had a rare condition that left her with slitted pupils. However, what is a useful adaptation in cats, giving them better vision, is caused by a detrimental mutation in a human. She was almost totally blind.

swampyankee
2017-Sep-23, 03:46 PM
Goats have funny eyes too:

http://hencam.com/static/uploads/2013/01/rectangular-eye.jpg

Goats are generally weird, although tasty and their milk makes good cheese.

WaxRubiks
2017-Sep-23, 03:55 PM
My sister went to college with a girl who had a rare condition that left her with slitted pupils. However, what is a useful adaptation in cats, giving them better vision, is caused by a detrimental mutation in a human. She was almost totally blind.

couldn't she have a cataract type surgery that replaced the lens with a lens with circular artificial pupils?

grant hutchison
2017-Sep-23, 04:24 PM
couldn't she have a cataract type surgery that replaced the lens with a lens with circular artificial pupils?The visual problem isn't primarily with the pupil shape. The developmental problem that causes coloboma iridis can affect other eye structures, too, from the eyelids to the retina. If you're lucky, you get away with a slot in your iris and no (or very few) problems with vision - but if you're unlucky, the slot affects the retina as well.

A circular artificial pupil would also give you a fixed aperture - blinded in bright light, unable to see in dim light. Whereas an eye with coloboma iridis adapts pretty well to lighting conditions.

Grant Hutchison

Noclevername
2017-Sep-23, 04:25 PM
couldn't she have a cataract type surgery that replaced the lens with a lens with circular artificial pupils?

I'm not sure of the state of medical technology at the time (1988) but I'm pretty sure if they could have done so, they would have.

Trebuchet
2017-Sep-23, 04:30 PM
Goats have funny eyes too:

http://hencam.com/static/uploads/2013/01/rectangular-eye.jpg

That's clearly an unusually hairy cuttlefish.

swampyankee
2017-Sep-24, 01:44 AM
My sister went to college with a girl who had a rare condition that left her with slitted pupils. However, what is a useful adaptation in cats, giving them better vision, is caused by a detrimental mutation in a human. She was almost totally blind.

It probably gives cats better night vision, but their visual acuity (https://www.canadianveterinarians.net/documents/marnie-ford-ophthalmology)and color vision are both inferior to many other animals, including humans.

WaxRubiks
2017-Sep-24, 01:53 AM
I read that cats aren't very good at processing visual information about, say something moving behind a fence, where as humans cane easily do that............!

publiusr
2017-Sep-24, 08:04 PM
Beetles have them too ;)
http://schwimmwagen.com/sites/default/files/styles/large/public/field/image/blackout.jpg

Put that light out!

NorthernDevo
2017-Sep-24, 11:18 PM
Goats are generally weird, although tasty and their milk makes good cheese.

Very tasty lol - about the only meat I like better than goat is the wild deer family of Canada; from Whitetails to Moose - but goat eyes remind me of horses' eyes. Goats don't have the little fan thing in the pupil that the horse does, but goats and horses both evolved on the plains; their eyes clearly show their evolutionary needs. The horizontal slit cuts out much of the glaring ambient light of the plains, allowing for clear vision through an amazingly wide arc around the animal's body.

Goats are marvellous, wonderful creatures in addition to being highly edible. Their eyes are only one of many amazing adaptations. I've heard of those adaptations but someone more knowledgeable than me should talk about them; my primary interest in goat is how well they go with potatoes and a little mint sauce. ;)

swampyankee
2017-Sep-25, 10:36 AM
Very tasty lol - about the only meat I like better than goat is the wild deer family of Canada; from Whitetails to Moose - but goat eyes remind me of horses' eyes. Goats don't have the little fan thing in the pupil that the horse does, but goats and horses both evolved on the plains; their eyes clearly show their evolutionary needs. The horizontal slit cuts out much of the glaring ambient light of the plains, allowing for clear vision through an amazingly wide arc around the animal's body.

Goats are marvellous, wonderful creatures in addition to being highly edible. Their eyes are only one of many amazing adaptations. I've heard of those adaptations but someone more knowledgeable than me should talk about them; my primary interest in goat is how well they go with potatoes and a little mint sauce. ;)

My father’s father kept goats. Among other things, he said they climbed trees.

George
2017-Sep-25, 01:44 PM
My fatherís father kept goats. Among other things, he said they climbed trees.

22652

I wonder what squirrels call them?

Trebuchet
2017-Sep-25, 02:45 PM
Goats in Trees Calendars (https://www.amazon.com/s/ref=nb_sb_ss_i_3_13?url=search-alias%3Daps&field-keywords=goats+in+trees+calendar&sprefix=goats+in+tree%2Caps%2C214&crid=2NS450I86IY0K) are a thing!

George
2017-Sep-25, 06:59 PM
Goats in Trees Calendars (https://www.amazon.com/s/ref=nb_sb_ss_i_3_13?url=search-alias%3Daps&field-keywords=goats+in+trees+calendar&sprefix=goats+in+tree%2Caps%2C214&crid=2NS450I86IY0K) are a thing!
The cliff notes aren't bad either.

22654

Swift
2017-Sep-25, 07:38 PM
22652

I wonder what squirrels call them?
Squirrels also call them trees. :p

George
2017-Sep-25, 08:12 PM
Squirrels also call them trees. :p

But the goats must drive them nuts! Hmmm, maybe that explains some things. ;)

Darrell
2017-Sep-26, 07:14 PM
For any late readers still interested in this discussion, here is a link to an article by a biologist which relates a recent paper about pupil shapes in animals. The article includes a link to the actual paper and touches on the hilights of the study. It's very interesting! Turns out that pupil shape is a bit more complicated than many people might think.

Why do animal species vary so much in the shape of pupils in their eyes? (https://whyevolutionistrue.wordpress.com/2015/08/10/why-do-animal-species-vary-so-much-in-the-shape-of-pupils-in-their-eyes/)

An excerpt from the article / study regarding vertical slit pupils.


That said, the advantage of having a vertical slit, for complicated optical reasons, diminishes as the eye gets higher off the ground. So the authors made and tested a prediction made from theoretical considerations:


We predict, therefore, that shorter frontal-eyed, ambush predators will be more likely to have a vertical-slit pupil than taller animals in that niche.

We evaluated this prediction by examining the relationship between eye height in these animals and the probability that they have a vertically elongated pupil. There is indeed a striking correlation among frontal-eyed, ambush predators between eye height and the probability of having such a pupil. Among the 65 frontal-eyed, ambush predators in our database, 44 have vertical pupils and 19 have circular. Of those with vertical pupils, 82% have shoulder heights less than 42 cm. Of those with circular pupils, only 17% are shorter than 42 cm.

Nearly all birds have circular pupils. The relationship between height and pupil shape offers a potential explanation. A near and foreshortened ground plane is not a prominent part of birdsí visual environment. The only birds known to have a slit pupil (and it is vertically elongated) are skimmers [Rynchopidae]. . .

Foxes, for example, have vertically slit pupils, but the taller wolves have round ones.

swampyankee
2017-Sep-27, 12:05 AM
But the goats must drive them nuts! Hmmm, maybe that explains some things. ;)

Goats are expanding into the niche once held by squirrels.

PetersCreek
2017-Sep-27, 12:27 AM
Goats are expanding into the niche once held by squirrels.

Then I'm gonna need a bigger live trap.

George
2017-Sep-27, 08:22 PM
Goats are expanding into the niche once held by squirrels.
How will squirrels adapt to their new abused environment?

This should be investigated as an evolutionary anomaly. Surely we can help the squirrels with all this by proper analysis, perhaps establishing a possible trend toward species extinction.
1) Are these all nannies avoiding billies? Whether some are recent wethers might be applicable. Speaking of weather...
2) Were there any flood predictions?
3) How much better is their view from up there? Were they lost like Bilbo?
4) Did they eat anything out of the ordinary like footballs?
5) Are they making any political statement that we or squirrels should be aware?
6) Did they read the old Llama thread here and get jealous?

WaxRubiks
2017-Sep-28, 12:36 AM
I think it points towards the extinction of a tree which reached into the sky where goats used to climb to Goat Land....now they just climb any old tree and don't know why...