(This typically affects children.)
This issue is actually a problem in gestalt psychology because these children and people do not see things as a whole necessarily but as different parts that they cannot sort or organize correctly in their brain or visual field, therefore, making it hard for someone to keep their place while reading, copying things from the board, paying attention to relevant words in a question, etc.
In simple terms, "figure" is what stands out and "ground" is what you put in the background, or don't pay attention to as much (i.e. peripheral vision). Here's a woman that explains this very easily from an experience she had:
What do you see? Which is figure and which is ground to you? This optical illusion is used commonly for this...