Reindeer’s Color-Changing Eyes

December 25, 2013 @ PopSci

Winter in the Arctic is grim. Reindeer manage to survive these gloomy weeks thanks to a peculiar adaptation. As the days grow darker, reindeer’s eyes turn from gold to blue.

A study published earlier this year in the Proceedings of the Royal Society B journal explained the science behind reindeers’ changing eyes. The color change happens in the tepetum lucid, which is the layer of tissue in the eye that reflects visible light back through the retina. This is the same component of the eye that makes cats’ and dogs’ eyes seem to glow in the dark.

In the summer when days and nights are marked by nearly constant brightness, the eye tissue is tinged gold, which is common for ungulates such as reindeers. But once the darkness of winter hits, reindeer eyes change their hue to blue. The change of color is also associated with a reduction in light reflected, and an increase in captured light. The increased retinal sensitivity comes at a cost, though—the acuity of the reindeers sight is reduced, meaning the sharpness or clearness of what is seen is lower.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s