There are quite a few tests online that claim to determine if you have perfect vision or if you have a high IQ. One of the latest tests involves reading the last number in a line of numbers. If you can read the last number, as it’s very faint on the screen, then you likely have perfect vision or vision that is good enough so that you don’t need glasses.

There are sets of five shapes, numbers and letters in a row. The first symbol is dark and is easy to see. Each symbol gets lighter and lighter until you get to the last one in the line. For some people, this last symbol is hard to see as it blends in with the background. The eyes have to work harder to determine what the last items are instead of clearly seeing them.

This final symbol can give an indication of the level of color sensitivity that the viewer has whether it’s high or low. The firs line features the final number as one that is difficult to see but not impossible. Each line of symbols has a line with the final image being harder to see. When you get to the final line, if you can see the last item, then it’s an indication that you have a high sensitivity to color.