S. R. Faruqi:

The wordplay is obvious: furoġh , shamʿa , jalvah , dīdah . In the verse there's the kind of 'delicacy of thought' that people usually assign to Ghalib. But rather than that, both these verses,

{95,6}

and the present verse, are good examples of the style that is called 'thought-binding' [ḳhayāl-bandī]. Shah Nasir popularized this style, then Nasikh and Ghalib took it to new heights. But as is clear from these verses, Mir too was fully a master of 'thought-binding'.

Before the beauty of the beloved, the radiance of the candle had fallen into eclipse. Therefore its falling into eclipse was pricking like a dust-grain in the eye of the Moth. Or else the radiance of the candle had become so pallid that it seemed to be foggy and obscured by dust; and this dust (that is, the deficiency in the beauty of the candle) was pricking in the eyes of the Moth the way a grain of dust pricks the eyes. Or else the eclipse of the beauty of the candle was a cause of sorrow to the Moth, and was like dust in his eye.

The pleasure is that if the eye would fill up with dust then nothing is visible-- thus the Moth remained deprived of the sight of the glory/appearance of the beloved, and it was unable to enjoy even the sight of the candle.

FWP:

SETS
MOTIFS == CANDLE; EYE; GATHERINGS; GAZE; JALVAH
NAMES == MOTH
TERMS == 'DELICACY OF THOUGHT'; 'THOUGHT-BINDING'; WORDPLAY

The idea of 'dust' in the eye offers a variety of possible meanings, all relevant: 1) the literal: physical dust in one's eye, so that the vision is obscured; 2) grief or vexation; 3) something contemptible or vile ('impurity, foulness'). This multivalence in the use of ġhubār (see the definition above) is what energizes the verse.

SRF finds this verse to be an excellent example of 'delicacy of thought' and 'thought-bindingness'-- the kind of thing that's usually associated with Ghalib. But delicacy or subtlety or refinement of thought is only a means to an end, and that end is the enjoyment felt by the reader. The present verse offers a moderate, adequate amount of such enjoyment, administered in a single jolt (the 'dust in the eye' of the Moth).

For a brilliant, overflowing amount, administered in repeated and cumulative doses, here's a verse of Ghalib's that similarly deals with tiny but emblematic worlds. Where Mir gives us the dust in the Moth's eye, Ghalib gives us the lamp-display in the bedchamber of the Moth's heart:

G{81,3}

The baroque, over-the-top quality of Ghalib's verse is even more conspicuous than that of the present verse. But its wild, free, intellectual play is an endless and un-pin-downable delight.