A Sika Deer (Cervus nippon) has excellent vision. It can detect movement from a long distance away. 

A Sika Deer does not have a round pupil, like the pupil of a human eye. It does not have a slitted pupil, like the pupil of a domestic cat. 

A Sika Deer has an elongated pupil. It looks like a raisin, or a flattened grape. 

A full arc of vision is 360 degrees. A human has an arc of vision of 120 degrees (a human cannot see objects behind it). A Sika Deer has an arc of vision of 310 degrees, which means that it can see almost all around it. 

A Sika Deer’s pupil can open very wide; wider than a human’s pupil.

A Sika Deer has better vision in the darkness than humans, and poor vision in the day time than humans. 

A Sika Deer has a reflective layer in the back of its eye, called a tapetum. The tapetum causes the eye to shine at night. It acts like a mirror, which is good for vision. 

A Sika Deer does not have a filter for ultraviolet (UV) light, like a human has. Therefore, it is sensitive to some colours, and movement, but it cannot see the fine details.

 

Photographer: Martina Nicolls

Martina Nicolls: SIMILAR BUT DIFFERENT IN THE ANIMAL KINGDOM