Optical configurations for head-worn see-through displays

An optical system comprising:

• a first combiner of a wearable head device;
• a second combiner of the wearable head device, the second combiner adapted to visually present image content such that a surrounding environment is visible to a user of the wearable head device through the second combiner while the image content is presented;
• one or more light sources, the one or more light sources adapted to project image light onto the first combiner and the second combiner,
• a first camera configured to capture a portion of first ambient light reflected by the first combiner;
• a second camera configured to capture a portion of second ambient light reflected by the second combiner;
• a first partial mirror adjustable to change a reflectivity associated with a first surface of the first combiner;
• a second partial minor adjustable to change a reflectivity associated with a first surface of the second combiner;
• and
• a processor configured to:
• determine whether a brightness of the first ambient light exceeds a first threshold value,
• in accordance with a determination that the brightness of the first ambient light exceeds the first threshold value, adjust the first partial minor to increase the reflectivity associated with a first surface of the first combiner,
• in accordance with a determination that the brightness of the first ambient light does not exceed the first threshold value, forgo adjusting the first partial minor to increase the reflectivity associated with the first surface of the first combiner,
• determine whether a brightness of the second ambient light exceeds a second threshold value,
• in accordance with a determination that the brightness of the second ambient light exceeds the second threshold value, adjust the second partial mirror to increase a reflectivity associated with a first surface of the second combiner, and
• in accordance with a determination that the brightness of the second ambient light does not exceed the second threshold value, forgo adjusting the second partial mirror to increase the reflectivity associated with the first surface of the second combiner,
• wherein the first combiner is adapted to reflect, toward a first eye of a user, a first portion of the image light projected by the one or more light sources, and
• wherein the second combiner is further adapted to reflect, toward a second eye of the user, a second portion of the image light projected by the one or more light sources.