S. R. Faruqi:

If we read .suurat ;xuub without the izafat, then the meaning becomes that her face now often wanders well (that is, with great fineness and clarity) in the wet eye. If we apply the izafat, then the meaning becomes 'fine face'. Ghalib has made much use of this style.

The phrase yih to ko))ii achanbhaa hai is related to the second line-- that is, is this any cause for surprise, that now her face wanders in my gaze? This kind of 'thought-elaboration' [;xayaal-aaraa))ii] (conceit) is common to Indo-Muslim and English 'Metaphysical' poets both.

FWP:

SETS == IZAFAT; KYA; MUSHAIRAH
MOTIFS == EYES
NAMES
TERMS == 'THOUGHT-ELABORATION'

Well, SRF's comments about the (optionally) present or absent izafat are very helpful, but I don't see why yih to ko))ii achanbhaa hai is to be related only to the second line. To me it seems a much better fit with the first line, of which it's a natural part. I don't even think it has a 'midpoint' relationship with both lines, though Mir is so fond of this particular effect.

For the first part of the first line reports a remarkable phenomenon: that the beloved's face/form can't be seen reflected in water. (In English folklore, it's sometimes a mark of ghosts or vampires, that they can't be seen reflected in mirrors, or in water.) Then the second part of the first line indignantly denies, with a strong, idiomatic flair, that this is at all surprising. (It asks a rhetorical question, and thus is excellently insha'iyah.)

Then of course under mushairah performance conditions we're made to wait as long as conveniently possible, before we're allowed to hear the reason that such a remarkable fact isn't really remarkable at all. Even when we're finally allowed to hear the second line, the punch-word that explains it all is deferred as long as possible, right until the rhyme-word. When (and only when) we hear chashm-e tar , the whole verse suddenly bursts into meaning. It bursts like a balloon in fact, and requires no further thought; after that moment of pleasure, we're ready for the next verse. This is the effect created by what I call a 'mushairah verse'.

The English term 'conceit' is supplied by SRF himself as an equivalent for ;xayaal-aaraa))ii ; he also supplies the English word 'Metaphysical', with no Urdu counterpart provided. This is the first time in his commentary that he has used the term ;xayaal-aaraa))ii , or the English words 'conceit' and 'Metaphysical'. This late entry of the terms is striking, since surely there have been quite a number of verses that could have warranted such a term at least as much as this one does. There's a lot to be said about the terminological perplexities of the ghazal world. I know that by inventing my own terminology I haven't necessarily improved the situation. But terms like 'mushairah verse' have proved invaluable for my own understanding.

Note for grammar fans: In the second half of the first line there's an entirely (contextually) necessary, but not literally present, kyaa .