Re: Effect of Eye Position on Perception

[P3D KENNETH LUKER <KLUKER@xxxxxxxxxxxxxxxxxxxxxxx>]

 Jim Crowell wrote:
> I'm pretty sure that what he was actually saying was that around the time
> of an eye movement, your perception of the _relative_ locations of objects
> is distorted.  E.g. that under certain circumstances you might perceive an
> object that is actually to the left of another to be to it's right.  I'd
> guess that it's a very small effect (i.e. that the two things have to lie
> close to a single line of sight) that only pertains for a small fraction of
> a second, which is why no-one's noticed it before...


One effect I have noticed has occurred at the time of a rapid eye
movement:  When I'm outside on a dark night, looking at the sky, I
will sometimes catch a glimpse of a flashing light--the strobe on an
aircraft wing, or on a distant tower.  I immediately move my eye to
the place I thought I saw the flash and wait for it to flash again. 
Most of the time, the next flash is at some distance from the spot
to which I moved my gaze.  On the second flash, I again correct my
direction of gaze to the new spot, and usually I've missed again. 
In fact, if the flashes are separated by more than a second or so in
time, it is VERY difficult to keep my eye on the flash, even if I
have a starry background to fix on.  This effect gives me the
feeling that the flash is really jumping around erratically. Light
pulses that are longer than an instantaneous flash are much easier
to track. 
Ken Luker
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Kenneth Luker
Marriott Library Systems and Technical Services
KLUKER@xxxxxxxxxxxxxxxx


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