The 'dent' refers to the wind blowing against the head of the wheat plant and causing it to bend out of shape. It 'lasts only a moment' as the wind quickly changes direction/speed and the dent disappears. It's 'as close as anyone gets to seeing the wind' because wind is invisible but here, you can physically see the effects of the wind (against the head of the wheat plant) Hope that helps!

"as close as anyone gets to seeing wind" = the closest anyone comes to the act of seeing wind with their eyes. You could think of a sentence like this. - We got very close to winning the game = We almost won the game, but actually did not. As my example shows clearly, "get" or "got" in these sentences means to come or approach near to the final goal. In your sentence it has to be "gets" to agree with the third person subject "anyone". There are two ways to interpret the structure, of which I believe only one is correct: 1. as near as anyone gets [to seeing the wind] = transformation from "gets [close] to seeing ... In this interpretation, "gets" and "to" are together by accident, and have nothing to do with the phrasal verb. I believe this is the only correct interpretation. 2. as close as anyone gets to seeing the wind = transformation from "gets to seeing the wind [(up) close]. This interpretation might be tempting but I think it's wrong. "gets to seeing" is problematic because the normal usage is "get to [INFINITIVE]", as in "I finally got to meet him". Do people also use "get to VERB-ing"? I think the answer is no.

The 'dent' refers to the wind blowing against the head of the wheat plant and causing it to bend out of shape. It 'lasts only a moment' as the wind quickly changes direction/speed and the dent disappears. It's 'as close as anyone gets to seeing the wind' because wind is invisible but here, you can physically see the effects of the wind (against the head of the wheat plant) Hope that helps!