We all spend so much time trying to get the tones in our photos to look exactly right, but just how accurate are your precious eyeballs? Color management company X-Rite has put together a test to see how well you're able to differentiate similar tones.
The test only takes a couple minutes and at the end, it asks for your sex and age so your results can be compared with others who have participated.
If you're working with an un-calibrated monitor, you probably shouldn't expect to do as well. Also, be sure to close your eyes for a few seconds every once in a while as you work. Opponent process will make the shades more difficult to differentiate the longer you stare at them. Remember the filters you used to use in the color dark room? Same deal.
The test has been around for a while, so you may have taken it before, but your monitor status and eye health change over time. Feel free to post your score in the comments. My first score of the morning was a 15. Not bad for a 28-year-old male, especially here at the beginning of allergy season.