View Full Version : Motion Induced blindness

09-09-2013, 10:33 AM
In a motor accident, wherein a speeding car hits a slower moving vehicle coming from the side, the car drivers often swear that they just didnít see the vehicle coming from the left or right. Well, they arenít lying. They really donít see the vehicle coming from the side, in spite of broad daylight. This phenomenon on the car driversí part is known as ďMotion Induced BlindnessĒ. It is definitely frightening.

Once airborne, pilots are taught to alternate their gaze between scanning the horizon and scanning their instrument panel, and never to fix their gaze for more than a couple of seconds on any single object. They are taught to continually keep their heads on a swivel and their eyes always moving. Because, if you fix your gaze on one object while you yourself are in motion, your peripheral vision goes blind. Till about three decades ago, this ďheads on swivel & eyes movingĒ technique was the only way to spot other aircraft in the skies around. Now-a-days they have on-board radars, but the old technique still holds good.

Let me give you a small demonstration of motion induced blindness. Just click on the link below. You will see a revolving array of blue crosses on a black background. There is a flashing green dot in the centre and three fixed yellow dots around it. If you fix your gaze on the green dot for more than a few seconds, the yellow dots will disappear at random, either singly, or in pairs, or all three together. In reality, the yellow dots are always there.

Just watch the yellow dots for some time to ensure that they donít go anywhere! (Click on the link)

http://www.msf-usa.org/motion.html < http://www.msf-usa.org/motion.html >

So, if you are driving at a high speed on a highway and if you fix your gaze on the road straight ahead, you may not see a car, a scooter, a buggy, a bicycle, a deer or even a human being approaching from the side.

Now reverse the situation. If you are crossing a road on foot and you see a speeding car approaching, thereís a good chance that the driver isnít seeing you, because his/her peripheral vision may be blind! And you may be in that blind zone!!

mark s
09-09-2013, 11:35 AM
There is tremendous complexity to vision that we don't usually appreciate. One of my favorites is that people (and animals) have brain visual pathways to detects eyes (someone or something looking at you). Ever have the feeling that someone is looking at you and when you turn your head someone is looking at you. Well the majority of visual processing is centered on only a few degrees of visual field (the light that lands on the fovea of your eye) whereas the photoreceptors in the rest of the eye(s) can detect light from greater than 180 degrees of field. Well the brain processes that information coarsely and mostly subconsciously. Interestingly the brain sorts this information to detect if a pair of eyes are gazing at you. If detected, these pathways get your attention (you feel like someone is looking at you) and you turn your head so that your fovea is in line with the perceived eyes. One can use this beneficially as a pedestrian or biker. If you are at an intersection with a car stopped or about to enter the intersection, always look directly at the driver. He will almost always turn and look at you thereby knowing that you are there, because by looking at him or her you have activated those attention pathways for visual gaze.

09-09-2013, 12:42 PM
That is also a good way to avoid being eaten by a predator stalking you. That may be one of the reasons why most of us are bothered when something interferes with the peripheral vision. I like the protection that a parka hood gives, but always felt a little uncomfortable until the "cobra" hood was developed. All of my hooded jackets have the cobra design hood now.