Not much gets past a dog's nose, but what about those eyes? What do dogs see when they gaze soulfully up at people or ogle birds and squirrels?
Dogs see in color, despite an old misconception, but their world still doesn't look quite like ours. While human eyes contain three kinds of color-sensing "cone" cells, dogs have just two, leaving them oblivious to red. Their lower visual acuity also makes everything look blurrier.
We may never know what it's like to be a dog — especially without their noses — but search engine Wolfram Alpha helps us guess, offering a dog vision tool that edits photos to mimic canine eyesight. Here are a few examples, republished with permission, in hopes of shedding a little light on man's best friend. (Text: Russell McLendon)