Those of us who've been reviewing The Adventures of Superman on MeTV lately have spotted a phenomenon peculiar to that show. Not only do Clark's best friends not recognize him as Superman when he's wearing his glasses...they also don't recognize him as Superman when he's not wearing them! Halfway into the series, there've been multiple episodes in which his supporting cast has gotten a good eyeful of him with his glasses off without even commenting on the resemblance.
A lot less than halfway, actually, since we're early in season 3 and it ran for 6 seasons.
But yeah, I was thinking that maybe it was the costume that did it, but there was one yesterday where Superman put on a hat and coat as a disguise and Jimmy, who was standing right there, didn't notice that he looked exactly like Clark Kent.
But they did this on radio too. There was a story where Kryptonite exposure caused Superman to lose his memory, and he ended up becoming a record-breaking baseball pitcher. Lois and Jimmy went to interview this pitcher, who didn't wear glasses, spoke in Superman's deep voice, and had demonstrated feats of superhuman athletic ability, and they immediately recognized him... as Clark Kent!


Having lurked somewhat in the M:I thread around here, I'm surprised somebody hasn't brought up the topic of how masks worked on that show....
That evolved over the first season. In the pilot, it was fairly plausible -- they brought in Rollin Hand to impersonate someone he already strongly resembled, using various prosthetic pieces, and when he later used a full-face mask to impersonate Dan Briggs (the original lead character), it was very brief and his eyes were hidden behind sunglasses, and he still spoke in his own voice. (I'm convinced that in some shots it actually was Martin Landau wearing a Steven Hill mask.) Later in the season, such a mask was totally convincing at close range and the voice could be perfectly duplicated, but one still couldn't eat while wearing the mask -- although I think it was in the same episode that David Opatoshu's character briefly wore a Rollin mask and magically lost his paunch while doing so. But by the end of the season, in "Shock," there was an enemy agent who wore a full-face mask for days of imprisonment, ate through it, sweated through it, even underwent electroshock therapy through it, all without the mask sustaining the slightest damage. So in less than a year it went from plausible to pure magic.
But speaking of the rules of fictional universes, what gets me is that, given how ubiquitous perfect masks are in M:I, you'd think that every nation's security forces would learn to check for latex masks as a routine part of a search.