If you want to take a close look on the file, you can download it at the link below.
This is a study I did of the human face/skin, most of the details were created from scratch using Blender and Substance Painter. I've sculpted the skin details using the default Blender's brushes, no alphas projection. The skin texture was created in Substance Painter, the eyes and the teeth textures were done inside Blender, using procedural textures.
Updated the file and all material setup to Blender 2.8, using Principled BSDF, Principled Hair BSDF and the new Random Walk method for the Subsurface Scattering.