Manufacturers have typically tackled the problem of outdoor LCD viewability by competing directly with sunlight, adding LCD backlights to increase screen brightness to 1000 nits or more. Unfortunately, those additional backlights sap precious battery life and don't address contrast or color saturation issues that continue to make screens look washed out in outdoor light.
According to Itronix, sunlight reflecting off LCD panel elements is the primary cause of that wash out. Traditional LCD panels reflect up to 20% of ambient light back to users, they say, and DynaVue addresses those reflections with a combination of "polarizing techniques and multi-layer indexed matched coatings to transform the frequency of the reflected light waves and eliminate reflections." There's no need for additional backlights, so battery life is unaffected. Itronix also says DynaVue is the only touchscreen to meet the Navy's MIL-L-85762A standard for viewability in all lighting conditions, so it's apparently good enough for cockpits.
Left: normal LCD display - Right: Itronix LCD display.