· Illusion is that due to subjective and objective reasons, people sometimes cannot completely and correctly perceive external things, which can lead to various distortions. Under certain conditions, human beings must inevitably produce objective things, something that has a fixed tendency and is distorted. Perception. Which of the following are not illusions:. ['In the dark, if people stare at a glowing point for a long time, they will find that the glowing point is moving.', 'When the moon is overhead, you will find that wherever you go, it always follows you.', 'Wearing white clothes will make skinny people slightly plump, while wearing black clothes will make fat people appear slim; clothes with horizontal lines will make people look fatter, clothes with vertical lines will make people look thinner.', 'Alone in bed, but felt like he was being picked up in a sedan chair.']