Closed-eye hallucination

The most basic form of CEV perception that can be immediately experienced in normal waking consciousness involves a seemingly random noise of pointillistic light or dark regions with no apparent shape or order.

In a bright room, a dark red can be seen, owing to a small amount of light penetrating the eyelids and taking on the color of the blood it has passed through.

Instead, if actively observed for a few minutes, one becomes aware of an apparent disorganized motion, a random field of lightness or darkness that overlays the redness or blackness of closed eyelids.

[1][2] When properly relaxed, it is possible to cause regions of intense black, bright white or even colors such as yellow, green, or pink to appear in the noise.

When lying down at night and closing the eyes, right before sleep or just before waking up, the complex motion of these patterns can become directly visible without any great effort thanks to hypnagogic hallucination.

[citation needed] Opening the eyes returns one to the normal physical world, but still with the CEV object field overlaid onto it and present.

If we remember that the essential difference between what we call the real world and the world of imagination and hallucination, is not the elements of which we build them up but the sequence in which these elements appear... then it follows that the sequences directed from without represent a limitation of the otherwise unlimited combinations of the selective forms released at random from within.This level can be entered from complete sensory deprivation, as experienced in an isolation tank or deep trance of hypnosis, but even there it requires great relaxation.

What happens at level 5 is likely that this system is inhibited, just like in REM sleep, by different causes like sensory deprivation, psychedelic drugs or meditative relaxation techniques.

CEV does not include entoptic phenomena such as "floaters", which are instead caused by opacities in the vitreous humour and often appear as cells or strands in the field of vision.

The retina can be made to produce light patterns of visual noise simply by one rubbing their eyes somewhat forcefully in a manner that increases intraocular pressure.