If you’ve ever gone into a dark room after being in a much lighter room, you’ve probably noticed that everything looked, well, dark. But after being in the dark space for awhile, you probably noticed that you were better able to make out the figures and furniture there, as well as distinguish between the room’s lighter and darker shades. This acclimation to the dark after being in the light resulted from your eyes’ ability to recover from oversensitivity to the highly contrasting stimuli of intense light and dark encountered in such a short period of time. The following illusion plays on this notion of oversensitivity and adaptation.
Notice that in the graphic, the bottom photo of the Alaskan floatplane is split into two sections of masked color: the section on the left (with the tail of the plane) is masked with a layer of cyan (light blue), while the section on the right (with the plane’s cockpit) is masked with a layer of light yellow. Meanwhile, the upper half of the larger overall graphic features the masked colors in the solid state, with the section on the left having been filled with cyan (light blue) and the section on the right with light yellow.
Without moving your eyes for at least 5 seconds, stare at the black dot in the middle of this upper area of solid colors. Then after the 5 seconds is up (or however long you choose to stare at the upper dot), shift your gaze immediately down to the dot in the middle of the photo of the floatplane.
Did you notice that the photo appears to be uniform, with the distinction between the cyan-masked half and the yellow-masked half completely erased? What you have just witnessed is the process of chromatic adaptation!
While the uniformity should have appeared to you for at least a couple of seconds after you shifted your gaze down from the the upper half of the graphic to the photo of the floatplane, you might have noticed that the distinction between the cyan half of the photo and the yellow half began to reemerge gradually (particularly after you stopped looking directly at the photo and moved your eyes away from it). While your eyes were initially “shocked” by the overload in color from staring at the first dot, they soon after became acclimated to the color distinctions in the floatplane photo.
This illusion, as you might have noticed, is somewhat similar to one that we posted back in November: “The Colors That Aren’t There”.
Illusion via here and here; graphic from http://www.personal.kent.edu/~rmuhamma/OpticalIllusion/illusion.html.