A caster is surrounded by enemies. He casts Hypnotic pattern, centering the 30-foot cube on himself in order to target a maximum of foes.
Each creature in the area who sees the pattern must make a Wisdom saving throw. On a failed save, the creature becomes charmed for the duration.
Being a creature in the area, the caster should be subject to the effect if he sees the pattern.
Can he shut his eyes in order to avoid being affected by his own spell?