Rico Buehler has told us about the Old Man Study project made at Vertex School, shared the sculpting workflow in ZBrush, and explained how the character's skin and eyes were set up.
Zbrush Old Man face sculpting Tutorial
Digital Sculpting - Sculpting the head in Zbrush
File Zbrush 3D Model - TurboSquid 1690960
My current project of an old chef, Rendered with Arnold in Maya : r/Maya
zbrush » Scott Eaton » Page 2
3D Ultra realistic old man HEAD 3D model
Sculpting an old man in ZBrush · 3dtotal · Learn, Create
Sculpting an old man hand, ZBrush, Timelapse, Sculpting
Making a Snow Dwarf in ZBrush, Maya & Arnold
3D Model Old Man Head - TurboSquid 1475109