At first glance, this image appears to contain nothing more than a hypnotic pattern of concentric circles. However, a three digit number is hidden behind the lines.
To make the number easier to recognize, step farther away from the screen, squint slightly, or view the image as a small thumbnail. This reduces the distracting details and allows the larger shapes to become clearer.
Some people notice the number immediately, while others need several attempts before all four digits appear.
Answer: The hidden number is 012
