A new image of an optical illusion has gone viral on social media, leaving people wondering how many numbers are hidden in the black and white swirl.
The image shows a swirl of black and white lines that look like they are spinning. There is a number in the center of the vortex, but it is not clear how many digits it contains. Some people see 4 numbers, others 6, and still others 7.
The reason for the differences in opinions lies in the different contrast sensitivity of people. Contrast sensitivity is the ability to distinguish subtle differences in brightness. People with high contrast sensitivity see details better in low light or foggy conditions.
In the case of an optical illusion, people with high contrast sensitivity can better see the numbers that are hidden in the vortex. They can discern subtle differences in brightness between black and white lines. People with low contrast sensitivity see numbers worse, and they can only see the general outline of the swirl.
Most people see five numbers in the image: 45283, but there are actually seven of them, and they are in this order: 3452839.