Notable things happening in the visual area are:
Increased Brightness as pupils dilate (depending on the injury this may be extreme to the point of whiting out. I can confirm this because I had this happen to me after Surgery once. It is unpleasant.)
Wonky focusing of the eye's lenses, could be represented by screen edge blurring
Tunnel vision, represented by an intensified vignette effect.
Possibly discoloration of vision in extreme states of shock, or loss of vision in head injuries.