Through The Eyes of A Dog- A Retouch on “How Do Dogs See You?”

Dog image

Check out our blog, International Dog Day- OphthPAWmology to see our fluffy coworkers!

Being a dog-friendly workplace and an ophthalmology-focused CRO… the idea for this blog was a no-brainer.

Jumping right into the subject at-hand, a dog’s eye structure is pretty similar to ours. Just like us, a dog has rods/cones, a retina, cornea, pupil, and lens. We’ve included a photo below to showcase a few of these similarities.

Photo of dog's eye
Minor breakdown of the canine eye

But as most know, healthy dogs have incredible low-light vision. Readers may wonder “If dogs have similarly structured eyes, what gives them better low-light vision?” to which I have two answers: rod-dominant retinas, and a tissue called tapetum lucidum. Before we discuss our new vocabulary words, let’s back-track and have a quick biology lesson.

According to Arizona State University, There are two types of photoreceptors involved in sight: rods and cones. […] Rods work at very low levels of light. We use these for night vision because only a few bits of light (photons) can activate a rod. Rods don’t help with color vision, which is why at night, we see everything in a gray scale. […] Cones require a lot more light and they are used to see color. We have three types of cones: blue, green, and red.

Are you still with me? Good. Looking back to our vocabulary words, dogs have rod-dominant retinas. As our source with Arizona State University mentions above, rods work at very low levels of light, while cones require much more light. The trade-off here lies within the rod-cone levels. Since dogs have more rods, they can see better in the dark. Inversely, due to having less cones (and less types of cones), color vision is estimated to be very limited for dogs.

 Color spectrum chart showing what dogs can see, vs what humans can see

 

On top of their poor color vision, dogs also are estimated to have visual acuity of around 20/75 which is considered nearsighted. But before you start feeling sad for your furry-friend, remember that dogs have incredible senses of smell and can essentially “see” the world in a completely different way than we can.

Here is a comparison of normal human vision (top) and estimated dog vision (bottom).

Image of normal human vision

Image of normal dog vision

Have an image you want to view in dog vision? Visit http://www.dog-vision.andraspeter.com/tool.php and select your file.

 

So, there you have it folks. Your dog can see you pretty well, if not too-distant. Great news all around!

 

Sources

https://www.asu.edu/

https://askabiologist.asu.edu/rods-and-cones