Houndsight isn't 20/20
Not much gets past a dog's nose, but what about those soulful eyes? What do dogs see when they gaze up at us or ogle a squirrel?
Despite an old misconception, dogs can see in color. Yet while human eyes contain three kinds of color-sensing "cone" cells, dogs have just two, leaving them red-green colorblind. Dogs also have less visual acuity than we do, which makes everything look blurrier, although they excel at motion detection and night vision.
We may never know what it's like to be a dog, especially without their sense of smell, but science can at least estimate what it looks like. The search engine Wolfram Alpha has a research-based dog vision tool, for instance, that edits photos to mimic canine eyesight. Here are a few examples, used with permission, to reveal the world as our best friends see it.
Editor's note: This photo gallery was originally published in August 2013, and has been updated to include new information.