The term waking screen refers to a variety of phenomena characterized by feelings of being surrounded or enveloped by transparent substances, creating a sense of being separated from the world. These symptoms are expressive of a wish to sleep, often, if not regularly, with a fantasy of being in the womb. Accordingly, the substances are often symbolic of the claustral wall. The waking screen is closely related to the dream screen which, it is suggested, is likewise a representation of the claustral wall. These symptoms may function as defenses against anxieties associated with conflicts arising at the more advanced levels of psychosexual development. They may also be manifestations of regressive instinctual longings evoked by frustration or loss. Depersonalization and derealization, which frequently accompany waking screen symptomatology, are seen to be components of the fantasies of sleep and return to the womb.