Metamerism is an interesting problem of colour vision and the term is used to describe situations where a colour looks the same as another, but measures as something different. Sometimes, colours measure the same, but look different. That’s a challenge and is, for example, one of the reasons why it took a while for monitors for use in colour critical applications took a while to be moved to LED backlights when they arrived. It turned out that colours that measured the same on the monitor looked different to the user on the LED-based monitors compared to CCFL-based devices. This was because of the different energy profile of the colour.
A team at the University of Wisconsin-Madison has developed a new approach to this problem by developing new glasses that turn the eye from being trichromatic (three detectors) to tetrachromatic (four colours), as some animals have. The glasses use blue filters, with slightly different frequencies, in each eye that are close enough to avoid discomfort, but far enough apart to make it clear when colours are different.
The filtered glasses show different colours at the top and bottom.
