Here's why:
* Football pool: This refers to a large, open container of water, typically used for recreational swimming or play.
* Wide: The comparison emphasizes the size and openness of the eyes, suggesting they are unnaturally large.
However, the comparison is somewhat awkward and unlikely. Football pools are typically quite large, and it would be very unusual for someone's eyes to be that wide.
More common and effective similes to describe wide eyes include:
* Eyes as wide as saucers
* Eyes as big as dinner plates
* Eyes wide with wonder/fear/surprise
These comparisons use familiar objects that are more relatable and easily visualized.
It's possible that the original phrase was meant to be humorous or exaggerated, but it's not a standard or commonly used expression.