Percussionistic

One of the things that make the marimba a very engaging instrument is the fact that you are not physically touching the instrument at any time. This is also true for the drums, but you don’t need as much precision as you need on the marimba. To make things more “engaging”, the marimba is very long, and you need to take some steps in order to move to different notes. No two bars are of the same width, which means you can’t get used to the distances between notes, because it would be different at every region on the instrument.
You can multiply all these factors by two while playing with a sheet of the music score, because your eyes need to be fixed on the score, and you have to “see” the notes while looking somewhere else!
Did I forget to mention that striking a note can be done on four different regions of each bar? The edge of the bar, the center, a bit off the center, and the node (which you don’t want to hit and kill the music, unless you intend to create that sound for a special effect).
My recommendation for visually maneuvering the instrument while playing a piece is to configure eye movements just like you would configure the sticking and which mallet to use to play which notes.
This applies mainly to playing without the notes, but can be even more critical with the notes in front of you. This means that, assuming you memorized the basic structure of the piece, and decided which mallets will play which notes, you will also have to decide on where your eyes will be looking during each bar, or at least when it is critical.
In some bars, you will have to play two distant notes at the same time. You need to figure out (and this is done case by case) which hand will be better prepared for the next note, so that you can easily strike that note without looking at it. At the same moment you would be looking at your other hand to ensure you have positioned it correctly.

Below is an example of how you might configure eye movements based on the needs of the marimba for that specific piece of music. L and R (left and right) correspond to which hand your eyes need to focus on that particular note or bar:

For the first bar and a half, you will have set your right hand in the position to play a repetitive pattern of notes for four times, and then you have to go down the scale gradually. Since your hand position remains the same (you only need to move mallet 4 inwards going down the scale), you don’t need to focus much on your right hand. The reason for the focus on the left hand is that you will have to jump from the low E and up to G quite often and throughout the piece. You will have to maintain a wide interval on your left hand and make big moves from note to note. No need to go through the details of all the notes, you get the point.
So while studying a piece and configuring the mallets and stickings, you might also want to determine the eye movements that best works for you to ensure you are hitting the notes properly.
I think with time, you will develop a sense of where to look at the right moment, but at the beginning it makes sense to put some conscious effort in that, just like you do with sticking.