Analysis of In Answer To A Request

You ask me for a sonnet. Ah, my Dear,
Can clocks tick back to yesterday at noon?
Can cracked and fallen leaves recall last June
And leap up on the boughs, now stiff and sere?
For your sake, I would go and seek the year,
Faded beyond the purple ranks of dune,
Blown sands of drifted hours, which the moon
Streaks with a ghostly finger, and her sneer
Pulls at my lengthening shadow. Yes, 'tis that!
My shadow stretches forward, and the ground
Is dark in front because the light's behind.
It is grotesque, with such a funny hat,
In watching it and walking I have found
More than enough to occupy my mind.

I cannot turn, the light would make me blind.