Why can't the poet rub strangeness from his sight in "After Apple-Picking"?

Essence of winter sleep is on the night,
The scent of apples: I am drowsing off.
I cannot rub the strangeness from my sight
I got from looking through a pane of glass
I skimmed this morning from the drinking trough
And held against the world of hoary grass.

The speaker of Robert Frost's poem, "After Apple-Picking" refers to a mysterious, abstract quality of "strangeness" that he initially picked up by peering through a pane of glass. The poem depicts the moment at which, while he is falling asleep, he realizes that the "strangeness" he picked up earlier in the day is still with him. In this passage, "strangeness" is at once the remembered scent of apples and a quality of vision.
Notably, the idiom of rubbing the strangeness from his sight plays off of the vernacular notion of rubbing the sleep out of one's eyes in the morning. But here, the "strangeness" is not of the night but rather from the day: it is like sleep in that it is hard to rub off of one's eyes but also like wakefulness, too, as it affords a peculiar sharpness to perception, as filtered through sense memory. Since the poem's central concern is with what it means to fall asleep—and less explicitly, by extension, what it means to be "awake" to the pleasures of life itself (as exemplified by the scent of apples)—we must take the slightly obscure poetic diction of the line "I cannot rub the strangeness from my sight," as being somewhat ironic.
Sleep is overcoming the speaker and presumably the strangeness of the day's perception will be lost to him: losing it is not a question of his own effort or lack of effort. What the speaker cannot "rub" from his inner sight is his tendency to think he can control sleep and wakefulness, which in this poem are akin to two dimensions of life that overcome the mind's eye, apart from human effort. Indeed, even the speaker's hazy perception of his own state of mind is "strange," caught as it is between the day and night.