Ask A Scientist

Why do animals see different than humans? Why can’t humans see in the dark?

Asked by: Maci Petrolle
School: Maine-Endwell Middle School
Grade: 7
Teacher: Kevin Wagstaff

Career Interest: Teacher, actress

Answer from George Catalano

Professor of Bioengineering

Research Area: Turbulence, Aerodynamics, Environmental Ethics, Modeling Ecosystems, Restoration of Wolves, Animal Rights
PhD school: University of Virginia, Aerospace Engineering, 1977
Interests/hobbies: All things Italian, especially Ferraris, Alfa Romeos and Ducatis, model trains and cars
Family: Wife, Karen, is a registered yoga teacher at Yoga for Everybody at the Orthopedic Associates; lives with 2 Alaskan Malamutes, four more in our hearts

Have you ever wondered what your dog or cat sees when he or she watches television with you? Do they see what we see or is it something entirely different? Until very recently, we humans were totally and literally in the dark about what and how other animals see. Modern science has revealed an amazing world of vision diversity.  Some animals see subtle variations in color, others can slow motion down to speeds that rival our most advanced high speed cameras, while still others actually detect heat variations much like the Hubble telescope. Let’s focus on a few different species and see how remarkably differently they see the world around them. 

Dogs are said to have dichromatic vision -- they can see only part of the range of colors in the visual spectrum of light wavelengths. Humans have trichomatic vision, meaning that they can see the whole spectrum. Dogs probably lack the ability to see the range of colors from green to red. This means that they see in shades of yellow and blue. Dogs can detect motion better and can see flickering light better than humans. Dogs likely see television as a series of moving frames rather than as a continuous scene. And what about our furry cat friends? Most cats can only detect a little color, and are best at focusing on one object narrowly (for hunting). But cats do have better night vision than humans.

Horses have an amazing range of vision – that is, except for seeing things that are right in front of them. They literally can’t spot whatever is between their eyes and therefore directly ahead, due to their binocular vision.

As the fall season continues to take firm root in Upstate New York, our skies are filled with migratory birds gathering together and beginning their long journeys to their winter homes. What do birds see? In fact, among our feathered friends there exists perhaps the greatest diversity in the ability see of all species. Pigeons, for example, can see literally millions of different colors and are thought to be among the best at color detection, compared to any other animal on earth. Eagles’ vision is also among the sharpest of any animal. Some can see twice as far as people. Studies suggest that some eagles can spot an animal the size of a rabbit up to two miles away. Canadian geese also have very good eyesight. They can see more than 180 degrees horizontally and vertically, which is very useful during flight. And they are able to fly at night and through terrible storms.

 

 

Last Updated: 9/18/13