Chromatic aberration

Chromatic aberration is a visual distortion that mimics the optical phenomenon of the same name found in photography and optics. In camera lenses, chromatic aberration occurs when different wavelengths of light are refracted by slightly different amounts, causing color channels to separate and producing colored fringes around high-contrast edges. The substance-induced visual effect replicates this phenomenon perceptually — the colors of objects appear to split into distinct, offset layers, most commonly separating into red, green, and blue channels that are shifted slightly out of alignment with each other.

The visual result is strikingly similar to viewing the world through red-blue anaglyph 3D glasses. Object edges acquire colored fringes. Surfaces that should display a single uniform color instead appear as overlapping layers of separate hues. High-contrast boundaries — the edge of a dark object against a light background, for example — display the most pronounced separation. The overall impression is of reality having been decomposed into its component color channels, each projected at a slightly different offset, creating a distinctly digital, glitchy aesthetic that many users find visually fascinating.

While the "classic" manifestation involves the RGB (red, green, blue) color split that corresponds to the three types of cone photoreceptors in the human retina, users occasionally report separations into other color combinations as well. The specific colors may vary, but the structural character of the effect — the splitting, offsetting, and fringing — remains consistent. Some users also report that the degree of offset varies dynamically, with the color channels drifting further apart and then partially realigning in a slow, pulsing rhythm.

The mechanism of this effect is not well understood, but it may involve disrupted synchronization in the color-processing pathways of the visual cortex. If the neural signals corresponding to different color channels are processed with slight temporal or spatial offsets — rather than being perfectly synchronized and overlaid as they normally are — the perceptual result would be exactly this kind of chromatic splitting. It may also relate to disruption of the same mechanisms that normally correct for the inherent chromatic aberration of the eye's own lens, which the visual system ordinarily compensates for seamlessly.

Chromatic aberration is most commonly reported with moderate doses of psychedelics including LSD, psilocybin, and mescaline, and it often co-occurs withcolour enhancement andcolour shifting. It is generally considered a benign, curiosity-level visual effect and is rarely if ever a source of distress.