GART

Scintillating Grid

Pale bars with a disc at every crossing. Dark spots appear in the discs you are not looking at, and never in the one you are.

Scintillating Grid: Pale bars with a disc at every crossing. Dark spots appear in the discs you are not looking at, and never in the one you are.Scintillating Grid: Pale bars with a disc at every crossing. Dark spots appear in the discs you are not looking at, and never in the one you are.

About this pattern

Elke Lingelbach, 1994 · after Ludimar Hermann, 1870

Scintillating Grid, optical illusion, drawn by GART: Pale bars with a disc at every crossing. Dark spots appear in the discs you are not looking at, and never in the one you are.
Scintillating Grid · CC BY 4.0

Hermann described smudges at the intersections of a dark grid in 1870; Lingelbach's version, with a disc placed on each crossing, made them flicker. The spots only ever appear away from the centre of vision, which is the point: the parts of the retina reading the corner of your eye pool light over a wider area than the part reading the middle, so what is averaged there is darker. Look straight at one and it has nothing in it.

TopicsOptical illusion (opens in a new tab)Grid illusion (opens in a new tab)

Behind the mathematics

Elke Lingelbach

The scintillating grid, 1994

German vision researcher who in 1994 found that discs at the crossings of a Hermann grid make dark dots flash, the scintillating grid.

Ludimar Hermann1838–1914

The Hermann grid, 1870

German physiologist who in 1870 described the grey spots that appear at the crossings of a white grid on black.