Saccaderrific
This morning I had a fascinating visual experience. It was about 5:30am and I couldn’t sleep so I stepped out on my balcony to just look around. The sky was a dark grey, both because of the position of the sun and the fact that it was lightly raining. I noticed that when I shifted my vision using my eyes I experienced a flash of lights moving opposite to the direction of the shift. It is hard to describe the appearance of the lights, but it was as if there were very faint, short, pseudo-line segments that moved quickly and disappeared just as quickly. Alternatively, they could be described as points, which when scanned across, created the appearance of short, slightly luminous, blurred lines. It was absolutely fascinating. I tested it repeatedly, and ever time I intentionally shifted my eyes, I experience these flashes distributed throughout my visual field for a split-second. I looked up, the flashes moved down. I looked left, they went right. I even tried going diagonally up and they moved diagonally down. Considering the possibility that it was some effect of my glasses, I took off my glasses to see if the phenomena continued. It did, though slightly diminished. Considering the possibility I was just imagining things I went back inside and looked around – no flashes. I then went back outside and saw the flashes ‘moving’ in the opposite direction of my eye-shift or saccade.
Minor, but useful, digression: Saccades are the quick, ballistic movements that your eyes make whenever you are reading or taking in a new scene or just looking around. You can see this when you watch someone else’s eyes and how they move about. This does not happen when you are tracking a continuously moving object (or move your head with your neck while keeping your vision fixation on something). The interesting thing about saccades is that they are happening all the time but we don’t notice. Our brain somehow inhibits the ‘visual smear’ that would result from the eyes moving from one place to another. Our eyes basically just ‘arrive’ at a new fixation point and our experience is that there was no jump at all.
So what the heck was happening with my eyes? I don’t know. I thought perhaps the inhibition of the smearing was itself slightly inhibited so I was seeing the appearance of movement in the opposite direction of my eyes. Another possibility is that my eyes were somehow globally taking in parts of the environment, like raindrops (that I could not see overtly) and somehow attaching to them; when I shifted my vision from these ‘set points’ they were used as a very brief anchor in my visual space. Consequently, it appeared as if flashes were moving away from my new gaze direction when in fact I was just looking past ‘set points’ that created the illusion of motion. I thought this might occur because the distribution of the flashes could be like how raindrops would appear if quickly viewed.
I really have no idea how plausible either of these scenarios is, but I do know the experience was interesting and amazing as it is extremely rare to be aware of the fact that your eyes are shifting when you examine an environment or scene. Of course, this would probably only be desirable temporarily as it would be quite negative if one was continually made aware of such shifts.
It makes me wonder if, on some level, I was able to see myself seeing.
Any thoughts? (No, I wasn’t on drugs :P)
Minor, but useful, digression: Saccades are the quick, ballistic movements that your eyes make whenever you are reading or taking in a new scene or just looking around. You can see this when you watch someone else’s eyes and how they move about. This does not happen when you are tracking a continuously moving object (or move your head with your neck while keeping your vision fixation on something). The interesting thing about saccades is that they are happening all the time but we don’t notice. Our brain somehow inhibits the ‘visual smear’ that would result from the eyes moving from one place to another. Our eyes basically just ‘arrive’ at a new fixation point and our experience is that there was no jump at all.
So what the heck was happening with my eyes? I don’t know. I thought perhaps the inhibition of the smearing was itself slightly inhibited so I was seeing the appearance of movement in the opposite direction of my eyes. Another possibility is that my eyes were somehow globally taking in parts of the environment, like raindrops (that I could not see overtly) and somehow attaching to them; when I shifted my vision from these ‘set points’ they were used as a very brief anchor in my visual space. Consequently, it appeared as if flashes were moving away from my new gaze direction when in fact I was just looking past ‘set points’ that created the illusion of motion. I thought this might occur because the distribution of the flashes could be like how raindrops would appear if quickly viewed.
I really have no idea how plausible either of these scenarios is, but I do know the experience was interesting and amazing as it is extremely rare to be aware of the fact that your eyes are shifting when you examine an environment or scene. Of course, this would probably only be desirable temporarily as it would be quite negative if one was continually made aware of such shifts.
It makes me wonder if, on some level, I was able to see myself seeing.
Any thoughts? (No, I wasn’t on drugs :P)
posted by That which is called Darren at 4:48 PM
2 Comments:
The effect could have been due to floaters. Floaters are bits of debris in the gel-like substance that fills the eyeball. Floaters are easier to 'see' when you move your eyes rapidly; a rapid shift down would make them appear to shift upward because their inertia keeps them from moving with the eye.
Thanks for the comment, but I have seen floaters that and the experience was very different. Luminosity, shape, amount, movement and other aspects were all different than my floater experiences.
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