Visual Perception:This term refers to the ability to interpret information and surroundings from visible light reaching the eyes.
Illusion: An illusion is a distortion of sensory perception, causing us to perceive something differently than its actual reality.
Sensory Deprivation: This involves reducing or removing stimuli from one or more of the senses - like being in a dark room with only one point of light (which can lead to experiencing the autokinetic effect).