I am not sure if this relates to the soldiers ability to see bombs, but if it depends on shadows, textures or other subtle clues it might.
I remember reading about research on the development of vision in kittens back in the seventies.
The name Marcus Jacobson comes to mind but I am not sure how direct of a link it would be. They were actually trying to study neurology when they were experimenting with the kittens.
Anyhow they found that if they raised kittens inside round solid cages painted with vertical stripes the kittens were unable to see things that were horizontal when they got older.
It was tied to certain critical periods in their growth.
The kittens never did learn to see horizontal stripes properly after they had grown past a certain age in the vertically striped world.

So maybe humans have similar critical periods to develop their vision skills too. Maybe if they are not exposed to ground textures they just don't develop the ability to see them easily.
If it is tied to critical development periods they might never be able to become proficient at it.