Seneca De brevitate vitae

There are a few things that are troubling me in this passage:

Quid securus et in tanta temporum fuga lentus menses tibi et annos in longam seriem, utcumque aviditati tuae visum est, exporrigis?

I think there is a gap in my knowledge of syntax. I don’t understand why visum is neuter. I seems to refer to aviditas which is feminine. Nor, for that matter do I understand why the latter is in the dative. I have a copy of Allen and Greenough but I haven’t been able to find the relevant passage. Could someone shed light on this?

I might be able to answer my own question. Is visum est an impersonal expression meaning 'it seemed proper/good"? So perhaps something like “…however it has seemed in keeping with your greed.”?

Yes, visum est is impersonal :+1: