I’m not sure if there’s something as healthy cataracts. Every case of cataracts has to be eventually treated by removal of your eye’s lens and then replace it with an intraocular lens (IOL).

If you meant if its ever done on a healthy lens, I’m not really sure. There’s a technique for installing an IOL on top of a previously installed IOL that’s called piggyback IOL, but on a healthy lens without cataracts seems uncommon.
Lensectomy and IOL placement can occur when the patient has a healthy lens in some cases though. When they’re going through other issues such as proliferative diabetic retinopathy, fibrovascular proliferation can occur in the vitreous humor, which would require removing it (the procedure is called vitrectomy). In some of those cases, the replacement of the vitreous humor accelerates cataracts development, which means that the lens will have to be replaced with an IOL.

That’s what comes to mind from my experience doing those exams many years ago, I could be wrong.