Add Eyelashes selection in the People mask in Lightroom Classic.

There are some standard masking based methods you can already use for these sorts of tasks without requiring a dedicated tool / AI assistance. IMO the key feature to grasp is that LrC tools can be quite loosely applied as to the WHERE, since the WHAT of their action is so progressive and so responsive to the image content. This is (in my experience) by contrast with the PS approach which encourages complex selection of WHERE an adjustment is to apply, and that becomes necessitated by that adjustment being itself quite simple in WHAT it is doing.

 It is possible to (to some extent) mimic the responsiveness of LrC within PS through the use of BlendIf and other more arcane means; though that can become hard work. Conversely, it is very hard to reproduce the PS approaches inside LrC. “Horses for courses”, as they say.

One idea for LrCis to use an intersection of two different kinds of selection within the same overall mask: one tone based (set to select only for the darker pixels) and the other a brushed selection (used to define, quite loosely, the general area where the eyes occur within that photo). Thus, your masking can refer indirectly to just the darkest parts within these loose areas, without any complex selection booundary drawin arround each eyelash . If the pupils are also getting picked up you can erase those out from this same brushing. This whole mask WITH its sharpening / darkening adjustments can then be given a name and saved wholesale in a develop preset.

Then the same preset can be applied onto a different photo, and the brushing altered to (loosely) indicate where the eye areas occur within that, and perhaps the tone selection / the adjustments that the mask is applying can be further tweaked, but only as needed.

Thus: that initial setup investment is paid for through later time-savings in use.