Half blinded by the glare on my windshield, I was waiting for the light at 75 th and Prospect to turn green. On the sidewalk stood an old man, short and a little stooped with three days of stubble on his chin. He was holding the arm and looking into the face of a tall, stoutly built man. The big man stared full face into the piercing morning sun and in his left hand clutched the harness of a resting, but watchful, yellow Lab. I imagine this tall man was blind and out on a training walk – a walk where the Lab was teaching him how to trust his trustworthy dog. The older fellow kept touching his arm to transmit a sense of security as, step by step, he pushes back the boundaries of his life without sight. My grand-dog, Zip, is a yellow Lab whose name came from the brown streak down his snout that makes it look like his face was zippered together. He’s just two years old but has become fast friends with my grandsons, loves to run with their dad and c...