sentence: Illusions are based on real perceptions, which are distorted or interpreted in a wrong way.
sentences_before: Usually people have to be awake and conscious to have hallucinations. That way, a person who sees or hears something that is not really there has a hallucination. Hallucinations are different from dreams. When people dream they are not awake. Hallucinations are also different from illusions.
concept_name: illusion
headings: Hallucination
categories: Psychology Health