On the contrary, hypnagogic illusion is, with me, a decided phenomenon.
The first is hypnagogic hallucination, the second coloured audition.
And there are crystal-seers who are not subject to hypnagogic illusions.
These ‘hypnagogic illusions’ Pontus de Tyard described in a pretty sonnet, more than three hundred years ago.
For bad visualisers, on the other hand, the vividness of these hypnagogic pictures may be absolutely a revelation.
In these respects, and in the awakeness of the scryer, crystal pictures differ from hypnagogic illusions.
The experience of hypnagogic illusions also seems far more rare than ordinary dreaming in sleep.