As we've talked about in a previous article, gamma can have a significant impact on colour reproduction on LCD monitors but there is a very quick check you can carry out that'll give you a rough idea on what gamma value your monitor is currently set to.
You need to view the following image on your monitor's screen but position yourself slightly back from the monitor then, while looking directly at the image, half-close your eyes. We're not saying this test is 100% accurate, but you will be able to roughly see what gamma value your monitor is currently configured to.
You need to visually compare the square outlines and the stripes around them, looking for patterns that appear to have the same tone of gray (brightness). The pattern for which the square frame and the striped pattern around it appear closest in brightness represents the rough gamma value of your monitor.
If you look at the 2.2 square and the frame appears dark, the LCD monitor's gamma value is low. If the square frame appears bright, the gamma value is high.