View Full Version : The blind spot
dpex
21st December 2008, 17:38
Ya just can't get to my age, alive, after all the mad shit I've done, without learning a bit, here and there.
And so, on the back of the missive about dehydration I'd like to impart a bit of knowledge about another, very deadly issue.
Your blind-spot.
If you sit and stare at a particular point then hold up your thumb upright at arms-length, then move said thumb left and right, you will find a point where you can no longer see your thumb.
It's normally a vector of about 7 degrees. This is your blind-spot. And you have one in each eye...presuming you have two eyes which function more or less normally.
The old catch-cry of, "I just didn't see you," has a foundation in human frailty, AKA, the blind-spot.
You arrive at an intersection. Your mind is elsewhere...the pretty blonde to the right, the bosses missive about sharpening up, the mortgage is due but the funds ain't there, the fucking IRD is all over you, you just found out your 'snip' didn't work and there's now yet another child on the way, and just to make matters worse, you just got a note from the school asserting your son has taken to beating up those who bully him.
All this is traversing you mind. Your eyes are wide open, but they ain't seeing everything.
Poom! From the right comes a cager who has right of way. You didn't see her because she was in your blind-spot. Next minute she's right there.
"where the fuck did you come fro?"...splat.
It's really important to keep your eyes moving. As you do your blind-spot moves out of the way.
Again. I've suffered the near-end in gliders. Fixated on what I'm doing (mainly trying to stay centred in a miserable thermal) tired, dehydrated, you name it. Poom! There's another aircraft which apparently came out of nowehere. Or a car, bike, truck, train, which my peripheral vision didn't see cos it was in my blind-spot.
We all have two blind-spots. There's no way in the world can you determine their exact position, therefore you have to keep your eyes moving, all of the time.
You'll be amazed at what appears from apparently nowhere, when you start working your eyes.
BTW: Dehydration exacerbates (makes worse) the blind-spot, because you go into tunnel vision.
Do the experiment. Hold out you right arm, thumb up. Stare directly ahead. Then move your thumb left and right. You'll find the point when you can no longer see you thumb. That's the serious danger point. That's the place where a cager is in, presuming you've seen him. But you didn't....Splat.
The Blind spot. Arguably, the biggest danger to bikers before cages were invented.
Road Guardian
21st December 2008, 18:03
It's really important to keep your eyes moving.
If there is anything you can take away from this article (good job dpex). It is that. Keep your eyes moving, and you will reduce you chances of having a collision, which anything.
Also on the tunnel vision thing, the faster you go the more your vision becomes narrowed. So the faster you go, the more you have to keep your eyes moving. Both sideways, (left and right) and forwards, remember the 12 second rule?
rainman
21st December 2008, 18:05
...presuming you have two eyes which function more or less normally.
So that's what I'm doing wrong then... :)
Good article (also the dehydration one) - cheers!
DUCATI*HARD
21st December 2008, 18:09
ya just can't get to my age, alive, after all the mad shit i've done, without learning a bit, here and there.
And so, on the back of the missive about dehydration i'd like to impart a bit of knowledge about another, very deadly issue.
Your blind-spot.
If you sit and stare at a particular point then hold up your thumb upright at arms-length, then move said thumb left and right, you will find a point where you can no longer see your thumb.
It's normally a vector of about 7 degrees. This is your blind-spot. And you have one in each eye...presuming you have two eyes which function more or less normally.
The old catch-cry of, "i just didn't see you," has a foundation in human frailty, aka, the blind-spot.
You arrive at an intersection. Your mind is elsewhere...the pretty blonde to the right, the bosses missive about sharpening up, the mortgage is due but the funds ain't there, the fucking ird is all over you, you just found out your 'snip' didn't work and there's now yet another child on the way, and just to make matters worse, you just got a note from the school asserting your son has taken to beating up those who bully him.
All this is traversing you mind. Your eyes are wide open, but they ain't seeing everything.
Poom! From the right comes a cager who has right of way. You didn't see her because she was in your blind-spot. Next minute she's right there.
"where the fuck did you come fro?"...splat.
It's really important to keep your eyes moving. As you do your blind-spot moves out of the way.
Again. I've suffered the near-end in gliders. Fixated on what i'm doing (mainly trying to stay centred in a miserable thermal) tired, dehydrated, you name it. Poom! There's another aircraft which apparently came out of nowehere. Or a car, bike, truck, train, which my peripheral vision didn't see cos it was in my blind-spot.
We all have two blind-spots. There's no way in the world can you determine their exact position, therefore you have to keep your eyes moving, all of the time.
You'll be amazed at what appears from apparently nowhere, when you start working your eyes.
Btw: Dehydration exacerbates (makes worse) the blind-spot, because you go into tunnel vision.
Do the experiment. Hold out you right arm, thumb up. Stare directly ahead. Then move your thumb left and right. You'll find the point when you can no longer see you thumb. That's the serious danger point. That's the place where a cager is in, presuming you've seen him. But you didn't....splat.
The blind spot. Arguably, the biggest danger to bikers before cages were invented.
i dont have a blind spot,,,i move too fast
FJRider
21st December 2008, 18:28
Not only the eyes must move, but it pays to move the head as well... dont move the head and tunnel vision sets in. You don't see because you don't/won't look...
A decent set of mirrors is helpful... adjusted properly...
scracha
21st December 2008, 18:30
Wot they all said.
Also
Please look over your shoulder before overtaking and changing lanes when in the car or motorcycle. Lotta bikers getting lazy out there and just relying on their mirrors......the quick glance has saved my bacon at least twice.
Trumpess
21st December 2008, 18:40
Thank you Dpex
An excellent topic to start the festive season and a timley reminder for the extra busy roads that maybe about to to scare the crappas out of us.
All advice is good advice!
Merry xmas and safe travels to you all!
trumpy
21st December 2008, 18:50
For those of you who rely heavily on your peripheral vision be aware that the far reaches of that vision is black and white (the various colour hues fade out at different places) so that bright red car on your far left (or right) is not red to your brain and may just fade into the general scenery. By the time it comes further into your vision and registers as a bright red moving object it may be too late to react and take avoiding action. i.e. move yer head!
And yes, I have done Keith Code's visual exercise and yes, the "middle distance stare" does work most of the time it's just that one time.............
98tls
21st December 2008, 19:22
If there is anything you can take away from this article (good job dpex). It is that. Keep your eyes moving, and you will reduce you chances of having a collision, which anything.
Also on the tunnel vision thing, the faster you go the more your vision becomes narrowed. So the faster you go, the more you have to keep your eyes moving. Both sideways, (left and right) and forwards, remember the 12 second rule? Actually no,never heard of it in 37 years of owning/riding.Do tell.
sinfull
21st December 2008, 19:46
Will get ya to show me that one on teusday mate buggered if i cant NOT see it till i lose it out past 180 degrees
AllanB
21st December 2008, 19:46
Thanks that explains it all.
The Blind Spot - obviously this is why I cannot find the G-spot.
:shifty::shifty::shifty::shifty:
SARGE
21st December 2008, 19:50
presuming you have two eyes which function more or less normally.
thats where my problems start..:stoogie:
beyond
21st December 2008, 19:53
He's quite right. Learnt this in the armed forces and did an article on Kiwi bikers a couple of years back. The reason motorists don't see you.
That blind spot is always there. When you look at a brick wall, around the centre of your vision you don't actually see the bricks but your brain fills in what it thinks you should be seeing.
At night particularly, to see anything dead ahead you need to be looking with your peridpheral vision as well, by turning your head from side to side. That's when you are trying to look in the dark, not driving with lights by the way.
dpex
21st December 2008, 20:10
Will get ya to show me that one on teusday mate buggered if i cant NOT see it till i lose it out past 180 degrees
You were doing slightly better than 180 degrees when you saw me give you the path to freedom, the other day. But, maybe your ears get in the way, most times. Must be hell to be listening to the coal burning while the real fuel is on it's way:--))
JohnR
21st December 2008, 21:39
Actually no,never heard of it in 37 years of owning/riding.Do tell.
The 12 second rule is the basis of searching and scanning technique in advanced driver training and is primarily used to determine the minimum distance you should be looking ahead.
Your vision should be out to a point at least 12 seconds ahead of where you are, you should then "scan" from one side of the road to the other
while bringing your vision back to just in front of you. Then check your mirrors! Repeat.
This should be a continuous process the whole time you are riding/driving.
It is also used to determine a safe distance ahead for overtaking. Because by using 12 seconds (rather than 100 metres advocated in the road code) distance increases with speed.
From memory your field of vision at 90 kmph is a cone of about 3 degrees!
You do the math as they say...I can't be bothered at this time of night.
Road Guardian
21st December 2008, 21:44
Actually no,never heard of it in 37 years of owning/riding.Do tell.
Are you talking about the 12 second rule?
If so, the 12 second rule, is a scanning technique. This is something I was taught when learning to drive an ambo. And as I have found out, it is very important to use when driving priority 1's (e.g light and sirens) and general driving as well.
Anyway, by using the 12 second rule, you are continuously scanning ahead of you where you will be in 12 seconds, rather than just concentrating on the traffic immediately in front and to the sides of you.
As you scan ahead, you are identifying any potential hazards and predicting what they will do, and acting on that said hazard earlier rather than later - and I mean, you are having a crash later.
Make sense?????
http://www.landtransport.govt.nz/roadcode/about-driving/safe-driving-tips.html
JohnR
21st December 2008, 22:05
[QUOTE=Road Guardian;1860066]Are you talking about the 12 second rule?
If so, the 12 second rule, is a scanning technique. This is something I was taught when learning to drive an ambo. And as I have found out, it is very important to use when driving priority 1's (e.g light and sirens) and general driving as well.
Anyway, by using the 12 second rule, you are continuously scanning ahead of you where you will be in 12 seconds, rather than just concentrating on the traffic immediately in front and to the sides of you.
As you scan ahead, you are identifying any potential hazards and predicting what they will do, and acting on that said hazard earlier rather than later - and I mean, you are having a crash later. [quote]
Glad to see the course is effective RG. :niceone: I don't know how long ago you did the driver training course but we are still preaching all the same things.:mega:
BTW I am a DI with St John in Auckland.
dpex
22nd December 2008, 05:26
i dont have a blind spot,,,i move too fast
Eh? I thought you rode a Honda???
vifferman
22nd December 2008, 08:14
Keep your eyes moving, and you will reduce you chances of having a collision...
Human eyes work best when there is something (noticeably) moving, otherwise the brain tunes it out. By moving your eyes and/or head, it means that things you'd otherwise not notice become significant to the parts of your brain that controls sight and warns you of potential danger.
That's another reason many drivers don't see bikers - they are too relaxed, staring fixedly ahead, and not scanning the road, whereas on a bike you are (or should be!) continuously scanning for hazards.
Winston001
22nd December 2008, 08:43
It's more complicated than just the blind spot. There is research which shows that we are still hardwired for the African savannah of our ancestors hundreds of thousands of years ago.
Our brains still have the primitive responses of ancient humans. A black stick on the ground is a potential snake - for a microsecond. Similarly trees, rocks, large objects are inanimate and don't move. So they are dismissed by the primal brain and ignored.
Cars are simply large rocks. Motorcycles do not look like a gazelle or any other animal = must be a bush/tree. Ignore.
We do over-ride the hind-brain with our modern perceptions but the point is, our instinctive reading of information has to be reinterpreted. If you are tired and distracted, its easy to simply ignore something.
portokiwi
22nd December 2008, 08:48
Not sure on blind spots but I am getting a bald spot on my head:crybaby:
Winston001
22nd December 2008, 10:40
Not sure on blind spots but I am getting a bald spot on my head:crybaby:
Too many U-turns under the sheets....:laugh:
scracha
22nd December 2008, 10:52
Cars are simply large rocks. Motorcycles do not look like a gazelle or any other animal = must be a bush/tree. Ignore.
See...Honda had the right idea with the urban tiger fireblade...
twinkle
22nd December 2008, 10:57
center your head on the screen
close your left eye
stare at the ball with your right eye
on your peripheral vision see what happens to the cross
Both your blind spots are on opposite sides, so as long as you have two eyes your brain compensates for the hole using the other eye. cool eh? :sunny:
Bass
22nd December 2008, 11:37
I believe the blind spot occurs because there are no receptor cells on your retina where the optic nerve attaches.
DUCATI*HARD
22nd December 2008, 17:23
Eh? I thought you rode a Honda???
DONT MAKE ME LAUGH,,,HA HA,,,HA HA,,,HA HA,,,ARE YOU THE GUY ON THE VESPA:bye:
nigel
22nd December 2008, 23:28
From memory your field of vision at 90 kmph is a cone of about 3 degrees!
You do the math as they say...I can't be bothered at this time of night.
At 100kph it's 22 degrees, according to relatively recent defensive driving material. 3 degrees really is tiny, you're talking less than the road width at more than 100m ;)
dipshit
22nd December 2008, 23:43
This is my favourite optical illusion. Proof that our brains do interpret what we see.
And if anybody doesn't believe it - print it out and cut out the A and B squares and swap them around.
JohnR
23rd December 2008, 08:23
At 100kph it's 22 degrees, according to relatively recent defensive driving material. 3 degrees really is tiny, you're talking less than the road width at more than 100m ;)
You're right, it was late and I must have been dehydrated...should have read 23 degrees.:doh::spanking:
dipshit
23rd December 2008, 09:01
Which is why the faster you go the more tunnel visioned you become.
Taking it a bit easier allows your peripheral vision to come into play more.
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