When somebody is watching something for so long they stop seeing details

In a scenario where somebody is watching trees go past out of a window looking for something they might stop noticing details and then miss what they are looking for because they have become accustomed to the mass of detail going past them.

What is the term to describe this? Word or phrase.

Solution 1:

"her eyes glazed over"

Example: "I was staring at the puzzle so long that my eyes glazed over." The term is often used as an expression of boredom or tiredness. For example: "After one hour of looking at his travel pictures, each one accompanied by a long explanation, my eyes glazed over and my mind went numb."

The best reference to this phrase is another question on ELU: Isn’t “Eye-glazing” a popular word? Why isn’t it included in major English dictionaries?

Solution 2:

White-line fever

Typically when you're driving at night, and unable to focus / keep it together because of staring too much at the white-lines.

Sensory overload

The technical term for this. But it's only one of the possible results, irritability, etc.