The Ishihara test is used to detect colour blindness, an anomaly responsible for colour vision deficiencies. To perform the test, sit about three feet away from your computer screen. Look at each of the circles below, what do you see?
If you are unable to see a 7, 13 and 16 in the upper row of circles and an 8, 12 and 9 in the lower row, you definitely have a vision problem. A comprehensive exam, performed by an optometrist is suggested.