S. R. Faruqi:

In the second divan, he's composed this very theme a little less well [{902,7}]:

javānī divānī sunā kyā nahīñ
ḥasīnoñ kā milnā hī bhāyā hameñ

[youthfulness, madness-- what have we not heard!
only/emphatically to obtain beautiful ones suited us]

In the present verse, in addition to the abundant expression of the enjoyableness of desire, there's also a subtle sarcasm toward oneself, that makes the verse distinguished among other verses of this kind.

Atish has brought out a new aspect of this theme. But in it there's the weakness that despite having an 'addiction to gazing', up to the present the heart is fine. In any case, because of the appropriateness of the idiom, Atish's verse has become an especially good one:

ātish un se nahīñ naz̤z̤āre kā lapkā chhuṭtā
merī āñkhoñ pah hai shāyad kih mirā dil bhārī

[Atish, the addiction to the sight of that one did not depart
it may be that my heart is heavier than my eyes]

In contrast to this, Hali's lapkā holds a mirror up to his temperament:

żauq sab jāte rahe juz żauq-e dīd
ik yih lapkā dekhiye kab jāʾegā

[all relishes kept going away, except the relish of sight
this is a single/particular/unique/excellent addiction-- let's see when it will go]

See

{11,6},

and

{43,5}.

On this theme the following verse is not without interest either. Janab Malik Ram, and following him Janab Arshi, have ascribed it to Ghalib [as an unpublished verse]:

G{273x,1}.

In Mir's present verse the point is also that the habit of staring and peering never went away. That is, in that time too when the heart was attached to some beloved and passion had overpowered him, even then the speaker didn't didn't renounce his gazing ways [naz̤ar-bāzī]-- he kept on looking at other beautiful ones with desirous eyes.

FWP:

SETS
MOTIFS == GAZE
NAMES
TERMS

It seems that tāk-jhāñk is a synonym for tāk (Platts p.305), so apparently no differentiation is intended between these two very similar verbs. SRF takes this activity as a kind of lapkā -- an addiction, a fetish, a letch. We're left almost with the idea of a peeping-tom figure, sneaking around catching possibly-illicit glimpses of beautiful ones at all costs, and under all circumstances. It doesn't seem too attractive a vision, but is there any other direction in which the verse wants to go?

It could be argued that the two lines have a cause-and-effect relationship: the heart is full of ardor for beauty, therefore the eyes are constantly seeking out new sights of beautiful ones. So perhaps the behavior of the eyes is a result of passion, so that it might be seen as tolerable (if not creditable). But there's really not enough in the verse to work with. To me it seems just a rather humdrum opening-verse.