Geniune squinting eyes expression ?
in The Commons
I've looked at many of the facial expression packs, but it seems like all of them are lacking this kind of expression, at least by judging the previews.
For reference: This or this is what I mean.
It's usually done with eyes fully closed, but mostly due to raised cheeks. And closed mouth with lips pressed together.
It's hard to classify this expression. Could be slight pain, or disgust, or getting tickled, or extreme joy..

Comments
AFE by D.Master has an expression like that (4th promo image shows it). I believe the female version has something similar.
Try doing it yourself with individual dials for eyes squint, nose scrunch, mouth dials, etc... You can also try Power Pose.
Already tried out power pose. I don't find it very useful. Rather work directly with the sliders.
So many wrinkles?! They look so old. A big No-No in DAZ Land! Just joking.
Like Pheonix1966 says though AFE is the best way to do that on DAZ 3D characters.
Sorry but PowerPose is going to be the best way to get the expressions you want even with AFE.
I did wish PowerPose had a way to turn limits on and off such that when limited you could change the expression more than a real person's muscles could.
...I would try a combination of several facial and facial morph sliders like brows down brow compression eyes squint, eyes closed, nose flare, mouth smile simple, mouth a bit of negative % to mouth open to clench the lips tighter and/or a bit of the "M" vesime.