In parapsychology and spiritual practice, an aura is a field of subtle, luminous radiation surrounding a person or object like the halo or aureola in religious art. The depiction of such an aura often connotes a person of particular power or holiness. It is said that all objects and all living things manifest such an aura. Often it is held to be perceptible, whether spontaneously or with practice: such perception is at times linked with the third eye of Indian spirituality. Various writers associate various personality traits with the colors of different layers of the aura. It has also been described as a map of the thoughts and feelings surrounding a person.
Skeptics such as Robert Todd Carroll contend that people may perceive auras because of effects within the brain: synesthesia, epilepsy, migraines, or the influence of psychedelic drugs such as LSD. Other causes may include disorders within the visual system provoking optical effects. Eye fatigue can also produce an aura, sometimes referred to as eye burn.
Attempts to prove the existence of auras scientifically have repeatedly met with failure; for example people are unable to see auras in the dark, and auras have never been successfully used to identify people when their identifying features are otherwise obscured in controlled tests