Yes actually I had already come to that same conclusion (that it might actually be a shadow.) Someone else posted a picture with the same effect that made me think of it, don’t remember exactly where I saw it now though. Try turning off cast shadows on the eyelashes.
the eyelashes don’t appear as an item in the scene tab so I can’t turn off cast shadows. There’s no shadows option in the shader tab either.
Give me a few hours for this new skin test render to finish and I will have a look for you. Do you have Uber Surface 2?
This why I like Area lighting as I don’t get this issue with unwanted shadows.