Diffraction

Diffraction is the experience of seeing rainbows and spectrums of colour embedded within the brighter parts of a person's visual field. This visual effect is likely due to pupil dilation, resulting in some light sources hitting the lens of the eye in a manner that appears to spread into a larger range of the spectrum rather than a consolidated wavelength.

Diffraction is most commonly induced under the influence of mild dosages of psychedelic compounds, such as LSD, psilocybin, and mescaline. However, this effect is also experienced during everyday sober living for certain people.