david shortridge put this sign up on his fence the beginning of the season. >> reporter: a glance won't help you truly see. >> we could only find white l.e.d. lights, so we had to spray paint the orange lights for bronco and we had to spray paint the blue lights for super bowl. >> reporter: one quick look at the sign on his fence and you and his neighbor put into it. make. >> reporter: or what david had to overcome to make it. >> his hands guided my blind hands and we shaped the letters. >> reporter: shortridge now 80, can only visualize what his work looks like. >> i can't even see anymore. entirely blind. but he doesn't need to see it. >> it's up for him. >> reporter: for him. shortridge's son gave up a career in california to move to care for his father, as a disease began to steal his father's vision. not long after that, sudden kidney failure stole his son. and cheering partner. >> sitting over in that couch, it was like we were in the cloud at the stadium. hands up and would scream. >> reporter: the letters on this fence are more than a fan's encouragement to a team competing in a