For some reason or another, Dr. Mid-Nite has long been one of my favorite comics characters.
I'm not entirely certain why. Perhaps part of it is his costume - it seems like a mix of Robin's costume with Captain America's boots dyed brown plus some other elements thrown in here and there. Or perhaps it's because he's likely the first "blind" superhero in comics. Or maybe it's none of those things.
I first encountered Dr. Mid-Nite in one of two places: It could've likely been reading the JSA chapter in All in Color for a Dime, or in a reprint in a DC Comics 100-Page Super-Spectacular (more than likely the latter -- I seem to recall getting a Batman one that had a Dr. Mid-Nite story in it).
His origin has elements of Two-Face and Batman in it: Dr. Charles McNider (gotta love that name, right?) was a surgeon who was operating on a witness due to testify in a criminal trial when a grenade is tossed into the operating room by said criminal. The resulting explosion left Dr. McNider blind, making him feel as though his days as a surgeon were over (this would be later echoed in Dr. Strange's origin story, naturally). Dr. McNider was brooding in his home when an owl crashed in through the window, causing him to remove the bandages covering his eyes, and making him discover that he wasn't truly blind in the conventional sense, but rather that his vision has been "inverted," so that he sees perfectly well in darkness, but is blind in daylight. He decides to use this ability to fight crime, creating two tools: His blackout bombs, which appear to be smoke grenades, but couldn't really just be that, since he could see fine in them (let's face it, if you can see in darkness, that doesn't help you see in smoke), and also his goggles that filtered out light. With these two inventions, he really didn't have a disability at all, but at least it gives him credibility when it's time to protect his secret identity.
He adopts the owl as a pet, naming it "Hooty," and embarks on his crime-fighting career. In his civilian identity, he begins a new career as a mystery novelist, dictating his stories to Myra Mason, his love interest and former nurse, now acting as his secretary. He'd later join the Justice Society of America, and was revived with the other JSA members in the Silver Age for annual JLA/JSA team-ups.
He's had two successors to his title: The first was Dr. Beth Chapel, who suffered a similar accident and took on the identity of Dr. Midnight (eschewing the spelling of her mentor's identity). She was introduced in the pages of Infinity, Inc, and after that series ended, she was killed off during the big Eclipso crossover event. The current Dr. Mid-Nite (going back to the original spelling) is Dr. Pieter Cross, a Norwegian man, and in the JSA, his role had been as the team physician.
In animation, the original Dr. Mid-Nite has appeared in a handful of episodes of Justice League Unlimited, and also at least two episodes of Batman: The Brave and the Bold.
Probably my favorite stories with Dr. Mid-Nite would be his appearances in Roy Thomas' All-Star Squadron, and this may be pure nostalgia going on. Up to this point, the only Golden Age stories I'd been able to read were those reprinted in the afore-mentioned 100-Page Super Specs, as there weren't any Archives editions or the like. Oh, wait, there were those tabloid books, too, in the 1970s. I'd only read a few of the original Dr. Mid-Nite stories before A-SS (unfortunate abbreviation, that) began, although I'd read a few of the Justice League of America issues the Society members appeared in, too.
Anyway, Roy didn't use him too much in that book, focusing instead on some of the other characters (like Liberty Belle, Johnny Quick, Robotman, and so forth), but he was in there, and certainly portrayed better than he had fared in previous appearances. I recall reading one JLA story that was part of the JLA/JSA team-ups where Mid-Nite had invented some kind of bizarre gun that seemed to do whatever was needed at the time... as if the writer of that story figured that he needed some kind of boost in power level to really work. Fortunately, this gun was Mopee'ed out (a reference to Mopee, an extradimensional elf that claimed in an issue of The Flash that it was he who gave Barry Allen his superspeed powers... since that story has been ignored by everyone since then, Mopee is often used to refer to something mentioned in one comics story that later writers decided was best to forget ever happened).
According to Wikipedia, the current comics have a version of Beth Chapel being a member of the JSA, or rather, Justice Society Infinity, but since I haven't read any of those, I can't speak to them at all.
Obviously, there's something appealing about the idea of a character who appears to be handicapped, but instead of letting that handicap stop them, it actually works for them. In the 1960s, Stan Lee came up with Daredevil, a take on the basic Dr. Mid-Nite idea, although Stan did take it a step further and used radar sense rather than the ability to see in total darkness (to be honest, that power works a bit better in the visual medium of comics). McNider was probably the only DC character in the Golden Age to have any disability at all, if not the only superhero in that era with any disability.
Also, unlike the vast majority of other comics characters who use "Doctor" or "Dr." in their heroic identity, Dr. Mid-Nite was an actual doctor (the only other real doctors I know of who used the title were Dr. Strange... I'm not sure Doom ever officially got the degree himself... of course there's Doc Savage, who preceded all those guys).
You know, when you think about it, it's kind of odd that nobody ever thought of having Dr. Mid-Nite having a relationship with Phantom Lady... after all, they kind of work much the same schtick... I'd imagine that Mid-Nite could see perfectly fine in PL's "blacklight ray," much as her goggles would let her see in Mid-Nite's blackout bombs. Sure, Doc had a love interest in the comics, but there had to have been the temptation to at least have them work together (I may have to ask Roy Thomas about this sometime).
I think the basic concept would still work today, if the right writer was working on whichever book any Dr. Mid-Nite would appear in... but somehow, I seriously doubt that DC would ever bring back either McNider or use either of the other Mid-Nites in any book. These days, they seem rather focused on trying to be "kewl" instead of being, well, good! Fortunately, for their bottom line, there's always the Archives and Showcase Presents volumes that occasionally get my money (as well as others of my generation of comics fans).