FCTM
Have none of you posters read your Boeing or Airbus FCTM? The very fact that you are even asking this question is very worrying.As a TRE, TRI, Instructor etc, if you are new to Jets, I will direct you to the FCTM.If you are new to type, I will direct you the FCTM.If you are new to big jets I will....well you get the point!
If you persist in staring at the touchdown zone below 50 feet radio altitude, you will be assisted in the flare OR hear the words "I have control..." You MUST look down the runway (three quarters is about right) as soon as you hear the "fifty" call either from the automatic callouts OR from the other guy, preferably just as the runway disappears under your nose, assuming you are on profile.The ONLY exceptions to this are
1. Low visibilty where the far end of the runway may not be visible.You should be either doing an autoland or if not available, a manual landing with a late AP disconnect (100 radio?) and use a very mechanical landing technique.....
2. Landing at Addis Ababa type runways where due to the runway contour, the other end of the runway disappears as you enter the flare...
The only reason I can think of why you are asking the question to start with is either you not a pilot, or have very low hours, or are poorly trained.