Reading with Bifocals (Revision 4)

[Lizzie]

Revision 3

A line of soldiers
slumps with shirts untucked, -- I can see why you made the word switch -- meaning wise, breaking on 'untucked' is superior
and one's foot drips -- this is the only bit that leaves me scratching my head. "One's" is ambiguous -- you could be talking about one of the soldiers, or (probably not, but it could be) that you're talking about the speaker, like their foot is dripping. I suppose you could be talking about anyone, really, but my money is on a soldier. Still, the ambiguity is distracting.
like a faucet with a tap tap tapping. -- like the sounds. You don't need 'with a' I don't think: like a faucet, tap tap tapping.
What started with sound -- good transition from the previous line
has ended in motion.
These hyperactive children -- like the idea of sugar being cocaine 
mainline sugar. Tiny cockroaches
scurry out of focus -- like the cockroaches bit too, how the 'out of focus' is like scurrying under a chair or behind a refrigerator.
into the uncertain darkness -- I like 'uncertain' better than 'cold' -- it's still not as punchy of a word as I would like, but maybe there's something to be said for understating it a bit, since nobody's falling off a cliff yet.
of middle age.

I do think that this is the best version.

Hope this helps.

Lizzie