Hi, it would help to have a bit more context about what it is your drawing, I see they are faces, but are they just regular human faces or are they robot/cyborg faces?
Tell us what you were trying to achieve and where you think it's working/not working.  I would suggest starting with a smaller canvas though, these are pretty big faces and I think the same visual message of them currently could be conveyed with something about 8 times smaller.

Here is a similar sized example to highlight what you can fit in that size canvas

Hi, thank you for your reply, but i am trying to make realistic human face and as you can see i am having problems with eyes and shading. I think there must be more than 2 colors, but i don't know how to do it.
I'll try to do with smaller canvas and i'll post outcome later.
Sorry for my bad english, i am from Russia(