Reindeer eyes change colour with seasons

Researchers have discovered that the eyes of the Arctic reindeer change color through seasons in order to adapt to the extreme changes in the light level in their environment and help detect predators. The eye color changes to gold in summer and deep blue during the cold winters.

Through this finding the researchers showed that this color change in the eyes of the reindeer helps them to see better in the continuous daylight of summer as well as the continuous darkness of the Arctic winters, by altering the sensitivity of the retina to light.

Prior to this, the same team had revealed how the Arctic reindeer eyes can also see ultraviolet light that is abundant in Arctic light but invisible to humans. The reindeer use it to spot predators and forage. They believe that the reflection of blue color in the eye of the reindeer is likely to favour ultra violet sensitivity.
From www.scienceworldreport.com