Dispersion - Binoculars
Dispersion or colour fringing is the phenomenon when the refractive index and therefore the wavelengths of different colours of light in the same glass are not the same.
This is the reason why light appears in all the colours of the spectrum when it passes through a prism. This is also why optical systems must be corrected for chromatic aberration, which would otherwise adversely affect the image quality.
Maar gelukkig zorgt dispersie ook voor mooie plaatjes zoals Pink Floyd lang geleden al wist!