Making a Color Disappear ポスター

Check your willpower: In this image there are five vertical light blue 'columns'. They seem to be vibrating and also appear to be very bright. But if you would focus and stare at any dark spot in the center of the image long enough - while slowly widening/narrowing the eyes - the light blue 'columns' will disappear. Each person may have another way to do the same. For example staring long enough strictly just at one spot within the light blue 'column' in the middle, would also turn the image uniform, without the bright blue colors.