I'm with Chuck on this one,
Even as I sit here trying to analyse where or what I'm looking at when I flare, I can't actually figure it out? I certainly don't gaze at the far end of the runway, never have! In fact, as I've often flown from fields with no actual runway there is no discernable runway edges to use in perhperial vision, and often just a crop line in the distance ... but it makes no difference to my landings (wish it did, perhaps they'd improve?). I remember the old "double decker bus" thing from gliding, but again, I've never thought that either. I'm kind of used to judging distances in the "up to 50 foot" region as a farmer using wide or long farm impliments and when I worked with my father as a proffessional fisherman, bringing a boat up to a bouy to haul lobster pots. I just "know" those distances. I'm sure I'm not unique, I think once most people have got their eye in, there's simply no science to it .... just good old human judgement!
SS