Contrasting hues of near-equal lightness produce uncomfortable vibrating boundary lines between them

When two colors are contrasting in hue but similar or equal in light intensity, their shared boundary produces a physiological vibration: the edge appears to duplicate, tremble, or show shadow/light haloes. Albers links this to after-image: the boundary’s local after-image interacts with the adjacent color to generate spurious hue at the edge. Conditions: high hue contrast AND close lightness (opposite of vanishing boundaries). The effect appears differently between observers, with and without glasses, at different focus distances — suggesting it is neurological rather than purely optical. The effect is aggressive and fatiguing; generally used only for attention-demanding advertising. In AV performance: this effect generates optical texture without actual movement, useful for intense visual moments.

Examples

Highly saturated orange and blue at equal luminance placed adjacent: vibrating glowing edge appears. In GLSL: two hues at equal Luma with high chroma difference produce this without animation.

Assessment

Create a color pair that produces vibrating boundaries. Then modify only the lightness of one color (not its hue) until the vibration stops. Explain what changed in perceptual terms.