Unique Olfactory Worlds (IMAGE) Monell Chemical Senses Center Caption In color vision, genetic variation in a single type of visual receptor leads to red-green colorblindness. Similar to the visual system, genetic variation in the olfactory system can alter perception of the olfactory world. This image was inspired by the Ishihara Color Blindness test, where colorblind individuals are unable to identify the embedded image inside each circle. Credit Joel Mainland Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.