Peripheral lighting for head worn computing

A head worn computer, comprising:

• a housing adapted to be worn on the head of a user, wherein the housing is adapted to hold an optical system;
• the optical system adapted to present digital content to a visual field of the user when the user is wearing the head worn computer, the optical system also adapted to be transmissive such that the user can view a surrounding environment through the optical system;
• and
• the optical system having an effects lighting system positioned to provide the wearer of the head worn computer with peripheral lighting effects in coordination with digital content presented, wherein the peripheral lighting effects are presented to an eye of the user after reflecting off of a partially-reflective partially-transmissive surface that is also used to reflect the digital content and through which the user views the surrounding environment, the peripheral lighting effects further presented outside of the visual field of view where the digital content is presented,
• wherein the partially-reflective partially-transmissive surface includes a tristimulus notch mirror.