I came across this and thought the information was rather interesting.
Up and to the Left
Indicates: Visually Constructed Images (Vc)
If you asked someone to “Imagine a purple buffalo”, this would be the direction their eyes moved in while thinking about the question as they “Visually Constructed” a purple buffalo in their mind.
From Eye Movement and Lying – How to detect lies – which features a direction for all sorts of things, smell, sound, memory…
Relatedly I’ve heard that people look one way when doing Maths problems in their heads and the other when doing anagrams. Unfortunately I have no-one to test it on at the moment, and I’ve forgotten which is left and which is right!