Oculoagravic illusion

An illusion engendered by horizontal linear acceleration which alters the effective direction of the gravitational force. It causes an upright passenger to feel tilted and to see the visual world as tilted. Apparent movement occurs when the accelerative force changes, and objects appear to swing into a new orientation. When such linear acceleration occurs in a vertical direction, a variant occurs which is also known as the elevator illusion. The effective force increases on the passenger when the lift accelerates on the way up or decelerates on the way down. With increasing force, the framework of the life appears to rise for a moment, while under decreasing force it appears to sink. An oculogyral version of the illusion is engendered with angular acceleration.