Riding Blind
Reporter: Jonica Newby
Producer: Steven Salgo
Researcher: Robyn Smith
Transcript
Related Info
2 May 2002
Youd think after thousands of years perfecting the
art of riding horses, everything there was to know
about horses would already be known. But, as Jonica
Newby reports, science has news for horse riders.
They may be surprised to discover theyve actually
been riding blind. A neuroscientist from Western
Australia made this amazing discovery while
investigating how horses see.
Not only did she find that the textbooks were wrong,
but she drew some extraordinary conclusions about what
horses can and cant see.
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Transcript
Narration: In the thousands of years weve been riding
horses, youd think wed know everything about how
horses see. But science has news for riders. They may
be surprised to discover theyve actually been riding
blind.
In science, just as in horse sports, its easy to be
blinded by tradition. Just because something has been
in the textbooks for a hundred years, it must be true.
So to see whats really there, sometimes it takes
someone to come along and look at it through fresh
eyes. In this case, the eyes to look through were the
eyes of a horse. When Dr Alison Harman took a fresh
look at how horses see, she never expected to overturn
all accepted wisdom. Shes a horse-rider and a
neuroscientist. And her quest began with a strange
accident.
Alison Harman: Years ago I saw a couple of people who
were practicing a dressage test with two people at
once, a pas de deux, and they both started cantering
around the arena and as they came to the bottom of the
arena, they actually crashed headlong into one
another. And at the time I thought, thats very
strange, why didnt the horse stop or something.
Narration: While intrigued, she didnt take it
further. But then Alison got interested in an equally
strange aspect of horse vision, described in
textbooks. This is Dukes Physiology, 1993 Edition. It
says that the horse has an eye unlike any other
animal. Its called a ramp retina and it works a bit
like bifocals. The horse puts its head down to see
long distances, and up to see short distances. And
thats what most of the textbooks have been saying for
the last hundred years.
Alison Harman: Well, I heard that the horse had a ramp
retina and I always assumed that that was true and I
didnt think about it very much and then one day I
started noticing that other animals didnt have one
and I wondered why a horse did. This time Alison was
determined to investigate. She got some horse eyes,
looked at the back of the eye, and found well
nothing unusual about the shape of the retina.
Alison Harman: Well, it just turned out that the ramp
retina was just a load of rubbish.
Narration: If it was so wrong, how did it go unnoticed
for so long?
Alison Harman: Well, I guess no one thought to look.
Well, this is not uncommon in science in fact. There
are a lot of times when people do just quote other
people without really thinking about whether they
should check the original reference and sometimes they
really ought to.
Narration: So if the long held theory of the ramp
retina was wrong, what else didnt we know about horse
vision? Curious, Alison decided next to dissect the
transparent retina from the back of the eye, and look
at the cells the horse uses to see.
Alison Harman: Well, what we found was that the horse
has got something completely different to what weve
got. Its actually got something called a visual
streak.
Narration: As this computer image of the retina shows,
the visual streak is a cluster of cells in a long
strip. By contrast, the human eye has a cluster of
cells in a tiny point. It means we see the world very
differently.
Narration: Its very hard for us to understand
actually because even if you put it on a piece of
paper and show someone, they think theyre just seeing
a wide picture. Theyre not seeing a wide picture,
theyre seeing all the way from there all the way back
to there and all the way back to there on both sides.
So its something that we really cant conceive of. To
us, this view of Kings Park is to the front only. But
a horse sees a clear, narrow strip running right
around 320 degrees. Above and below that strip is
blurred. Whats more, it cant see the colour red.
There was just one more major test to do. This was a
test of the limits of the horses vision. Just how far
could it see forward, up, down and sideways. And
thats when Alison got her biggest surprise.
Alison Harman: OK, make sure hes got his head
straight. OK I can see eye shine round to there.
Narration: An ophthalmoscope was used to look at the
shiny retina, and determine the horses field of view.
Alison Harman: When I go across here, its gone. Its
not going across here at all.
Narration: To Alisons astonishment, the field of view
ran in the direction of the nose.
Alison Harman: Instead of it being in front of their
head the way it is for us, its actually down their
nose and sort of towards the ground.
Narration: Above and below the nose, the horse simply
couldnt see. Suddenly, Alison grasped the disturbing
implications for how we ride horses. Because when the
horses head is loose, it can put its nose up to look
forward. But when a horse is ridden in the classical
position, its nose points down.
Alison Harman: It was a bit of a shock to discover
that in fact they cant see when their heads are
pulled in like that. And its really rather a scary
thought that people are riding around so much these
days with their horses like that.
Narration: To demonstrate what she means, Alison takes
me to the arena. Well, this horse has been
traditionally trained and Im going to ride her around
with her head in a whole lot of different positions,
and well just see what happens.
Alison Harman: Okay now Jonica is riding the horse
quite over-bent with the horses head behind the
vertical. What it actually sees when its head is right
down low and behind the vertical is its really seeing
the ground in front of its feet. It cant see whats
directly in front of it. Jonica, can you try and ride
the horse now on front of vertical. Yes, thats almost
better there. Thats more or less right.
Jonica Newby: But there is a disadvantage to riding
like this. This horse doesnt know me or trust me. I
realise now she can see, she wants to think for
herself.
Alison Harman: Now it doesnt feel as safe to Jonica
Im sure because she feels that the horse is going to
start spooking, because it can actually now see where
its going.
Narration: Which is exactly what happens next. A
sudden movement. The head goes right up. And were
spooked.
Jonica Newby: Shes a bit of fun today.
Alison Harman: Yeah, that was a great spook that one.
Narration: Alison now believes this so called
spooking behaviour is the reason the nose down
position became popular in the first place. To the
rider, the horse feels more obedient like that. What
no one ever realised is that its obedient because it
cant see where its going. At last Alison understands
why those earlier horses crashed.
Alison Harman: I now realise the reason they didnt do
anything was because they couldnt see, they were
assuming their riders were guiding them safely, and
the riders werent looking where they were going
either.
Narration: While Alison doesnt expect the grand
traditions of riding to change, she does want riders
to understand their responsibility. As for Alison
herself, shell never again ride her horse blind.
Alison Harman: I would rather have a horse which is
calm and obedient and submissive but able to see at
the same time, because I know it really is being calm
and obedient then. Its not being submissive because
it has to be. Because it cant see.
Related Info
Alison Harman, University of Western Australia
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