I think that this is a really good approach to beginning creating a wound for a broken bone as an extreme injury. This is because there are many tones and there is depth in colour to make it look like a deep cut. To develop this and adapt it I would add a few more varieties of tones at the top to create realism.
This is by far the most realistic looking picture I have seen yet creating the illusion of a missing eye. You can really see the depth and darkness of the hole, and the blood trickling down her face just completely brings the whole image together.