Hi there!
Good concept and very well-thought out post!
I think that what you said is a big part of it...however I think that mental and dream thoughts make their way through the cord, too. Perhaps because the astral body is "losing reception", it panics and tries to invent stuff to make up for it...either that or the lack of energy permits thoughts to come through...
I still agree, at least partly, with Robert Bruce's theory about seeing things from the past that have left a mental impression. However, I think they co-exist with the mental thoughts that tend to come through and create one hybrid mishmash in your visual field.
I think that the mental "artifacts" exist on a lower vibration or plane of consciousness than the real-time zone itself. When one has a enough energy to see clearly with no distortions, I think it is because we are on a slightly higher portion of the astral plane or level of consciousness and therefore tune them out. Likewise, when we start to run out of energy, we tune back in to them and see the distortions at the end of our projections.
before I start, I would like to say i have an intense intrest in the mechanics of what happens in the OBE process and the mechanics of the astral dimension, here is a theory I wrote up earlier, feel free to read :)
What causes vision distortion?
The very problem that plagues OBER"S both beginner and advanced, I have heard theories about this, when one is out of body, there consciousness seems to transfer to the astral double, properly via the astral cord, how ever, when vision and even mental clarity seems to fade, in forms such as ex: blurred vision, milky like substance, fogginess etc, it could be due to, first and for most, lack of focus, since we are in possession of two entities, that being, your human body and your astral body, when we loose focus while OB, the astral double may seem to "loose reception" a good analogy of this can be like a cell phone, when you have your cell phone in an area of very low to no coverage, the signal gets so weak, that the phone steps down, and goes back to a search mode "searching for network" the same thing may happen while OB here is a chain of events comparing the two:
Cell phone--> loosing reception--> total loss of reception--> back to search
Physical body-> separation (tune into astral)-> OB-> loss of focus-> visual/mental clarity fade->total loss of consciousness or visual (black void)->back to physical body (astral body attempts to retune to astral dimension or a reset)
So when you loose clarity or totally black out what ever it may be consciousness or visual or mental or any, your astral body says, "well I am no longer in tune with the astral and ends in the "void" I better go back to my physical body and try and retune to the dimension, perhaps the chant, "clarity now" helps with focus and staying in "tune" in the astral.
The black void:
Many times I and many other OBER"S have come across a void, you are conscious and aware, you are in your astral double at this stage, how ever, nothing but void surrounds you, this may last seconds or minutes, you may come into the void, by either, loss of focus (read above analogy) or during the separation of astral body (astral blindness) or during lucid dreaming when the subject in the lucid dream looses focus and the dream scene totally disappears into a dark void of nothingness but awareness may remain and they may wake up.
I have a theory about this void, the void seems to be a place where the astral body tunes into the astral dimension, a "time out zone" so the astral body may say, ok, I am in the void, let me tune into the astral dimension, its like when you tune your radio and while your searching all you get is static, I am very interested in this void, perhaps the void is a huge gate way to other higher dimensions, perhaps if you arrive accidentally in the void, you can tune other dimensions, such as mental, budhic etc, perhaps astral blindness may be due to the fact that the astral body has not fully tuned into the astral, and when visuals returns, it's fully tuned in, its interesting to note, that consciousness is first tuned in, than visuals afterwards, now many may say, well how come I can see through my eyelids during the separation process? Well, I to have seen through my eyelids a few times, but it quickly dissipate back to the void but with awareness still activated, during this, you get the usual symptoms, vibrations, sounds, bangs, voices etc, but I will stay with my theory of lack of mental focus, now these are just theories,
I have read about bio-magnetic hold causing astral blindness, a good theory, but, there has to be more than that, I do not believe the astral body is made of energy like any thing found in the 3rd dimensional universe, so I seriously doubt, any form of magnetic energy could alter it, feel free to discuss this, I am not saying this is the utter truth, but, I would love to hear your opinions and theories on the matter.