Eyesight. Is there a definite test?

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poiuytrewq

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Horse reacts to movement directly near his eye and see's fencing, steps etc so he has sight.
I wondered if there is a more fine tuned way of testing sight in horses?
 
Your vet will be able to examine the eye and advise on changes and cataracts along with guidance to the level of sight. Many horses have age related changes that will bother them as the years go by.
 
To get a full picture, you need to go to an opthamologist. They are few and far between, and a full exam costs a fair bit. I had a horse for sale that was eventing, eyesight fine, but at a vetting a cataract was noted. This was nothing like the usual cloudy disc, in fact, I couldn't see anything at all. It turned out after an expensive trip to AHT, that the horse had been born with it, and his sight was excellent, and wouldn't deteriorate.
 
It's not a massive deal. Horse in question lost all vision due to an injury last winter. It was short term and it came back with treatment.
However he's spooked a few times at nothing, but big spooks- unlike him, he usually doesn't spook at things other horses might. He also walked into me a few weeks ago out in the field.
His eyes have been looked at and are apparently fine but just routine by a normal vet.
 
There are definitive fails but it's difficult to get a definitive pass. I had a horse who was terribly jumpy from when I bought him, and I backed him but he proved impossible to get 'ridden away'. I doubted his peripheral vision and the vet was very surprised to confirm that he had lost cells around the edge of the retina, but said that he was still a pre purchase vetting pass and that it would not get any worse. Three months later, he was blind in one eye and nearly blind in the other, terrified, and I had him put down. Four years old, such a shame :(
 
ycbm said:
There are definitive fails but it's difficult to get a definitive pass. I had a horse who was terribly jumpy from when I bought him, and I backed him but he proved impossible to get 'ridden away'. I doubted his peripheral vision and the vet was very surprised to confirm that he had lost cells around the edge of the retina, but said that he was still a pre purchase vetting pass and that it would not get any worse. Three months later, he was blind in one eye and nearly blind in the other, terrified, and I had him put down. Four years old, such a shame :(
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Was that a 'normal' vet who spotted the lost cells? My mare is definitely worse on her left side but has been checked twice and nothing obvious.
 
cundlegreen said:
To get a full picture, you need to go to an opthamologist. They are few and far between, and a full exam costs a fair bit. I had a horse for sale that was eventing, eyesight fine, but at a vetting a cataract was noted. This was nothing like the usual cloudy disc, in fact, I couldn't see anything at all. It turned out after an expensive trip to AHT, that the horse had been born with it, and his sight was excellent, and wouldn't deteriorate.
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I had exactly the same experience, took the mare to an equine opthalmologist near Leominster several years ago. She kept the mare in the trailer, blocked out as much light as possible and examined the eyes, didn't cost a huge amount if I remember rightly. She did say examining an eye without a suitably darkened space was a waste of time. If you speak to your vet OP they will know the nearest one to you
 
Was that a 'normal' vet who spotted the lost cells? My mare is definitely worse on her left side but has been checked twice and nothing obvious.
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Yes, just an ordinary vet with a, standard eye 'thingy' that they use for a vetting. She said it wasn't obvious and she only realised it was significant because I could show her that he lacked peripheral vision. I tested him for that by putting a finger up to his eye from various directions, and he definitely couldn't see it when it was coming from behind him. She was shocked, she said it's very unusual to see anything wrong with the retina of a four year old.

She said I could refer him to an eye specialist but that there were none anywhere near us. She also didn't think it would make any difference to refer him because there was nothing that could be done, and she was absolutely positive that it wouldn't progress, but it did.


There are left and right eye differences in horses. Is it possible yours is an extreme example of this:

https://www.ncbi.nlm.nih.gov/pubmed/19618222
 
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ycbm said:
Yes, just an ordinary vet with a, standard eye 'thingy' that they use for a vetting. She said it wasn't obvious and she only realised it was significant because I could show her that he lacked peripheral vision. I tested him for that by putting a finger up to his eye from various directions, and he definitely couldn't see it when it was coming from behind him. She was shocked, she said it's very unusual to see anything wrong with the retina of a four year old.

She said I could refer him to an eye specialist but that there were none anywhere near us. She also didn't think it would make any difference to refer him because there was nothing that could be done, and she was absolutely positive that it wouldn't progress, but it did.


There are left and right eye differences in horses. Is it possible yours is an extreme example of this:

https://www.ncbi.nlm.nih.gov/pubmed/19618222
Click to expand...

Interesting article! Its actually her left eye that I think she has a slight issue with, but the vet couldn't spot anything when examining her (in a dark stable). Might try some of the peripheral vision tests on her. She is the horse that likes to educate me in unusual medical issues so the chances of her having something odd are pretty high........
 
Friends horse was very spooky at one time so the first vet looked in its eyes and said his epitheralial layer had to many cells and it would cause the horse to problems with what he saw in the one eye, it would have trouble making out shapes or something, dark and light also. Then she got another vet to look a few weeks later and the second vet couldn't see any additional cells present that would make the first vet think this. I think the vets were from the same practice.I know her horse has always been spookier on the one rein so she tends to lead him from this side to stop the horse from shying into her which it rarely does. I heard that if you hold a flame to the eye you should see an upwards flame, a downwards flame and one on its side, something to do with how light is bounced off the retina and that all eyes should show the same image if they are functional.Not sure if I have explained that right, sure someone who is an optometrist will explain it better than me but that was the jist.
 
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Not to say this applies to your horse. I has a 16 year old whose eyes were obviously going, he was spooking at nothing and was often surprised by things. The junior vet examined him and said his eyes were OK and there was no cataract or damage to the optic nerve. He then went repeatedly lame and was tested positive for Cushings. The senior vet, when I consulted him about the eyesight issue, said that the swollen pituitary gland was probably pressing on the optic nerves inside the brain and causing sight loss. He deteriorated and we lost him but it was an interesting lesson in eye issues.
 
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