Faces Critique

Hey, I have realized I don't spend much time on faces. This is my progress so far. Any comments and critique is welcomed.

https://imgur.com/a/0LAXmaa

Hello, I like your drawings. The boldness in your shading gives a very dramatic effect. I guess the lack of shading on the forehead makes it look flatter than the sides of the face? I feel like the temples and the part of the forehead near one’s hairline sometimes fall into shadow when facing a model straight on. I think because the slope of the skull and also if the hair is casting shadows on the face. I like how you did the eyes. I struggle to add so much detail to any feature without muddying them but your eyes are very readable if that makes sense? Thank you for posting.