Slit Vision

Posted by Laura Jackson on January 4, 2004

Q: I was wondering what animals, if any, have horizontal slits instead of vertical slits. Is there any significance to the vertical vs. horizontal slits?

Thanks for such a great website!

Thanks, Laura Jackson

A: Most of the ungulates (horses, tapirs, pigs, deer, antelope, cattle etc.) have horizontal pupils. As I understand it, the horizontal pupil permits greater peripheral vision. These animals are preyed upon by a variety of carnivors and their vision is critical to their safety. If they can see danger more easily out of the "corner of their eye", they're more likely to avoid capture.

John Wiessinger ( January 5, 2004)

Filed under: Mammals