In one of my favorite episodes, the MythBusters tested a theory on why pirates are classically depicted as wearing eye patches. Was it to cover empty eye sockets, or because of some more mundane aspect of their shipboard lives?
The MythBusters concluded that pirates wore eye patches to keep one eye fully dark adapted, something astronomers have also done for centuries. It takes as long as 30 minutes for the human eye to fully adapt to darkness, but, fortunately, our eyes adjust independently to light conditions. So, pirates wore patches over one eye to keep that eye dark adapted, while using the other eye for drinking, fighting or pillaging on the main sunlit deck
Similarly, before looking through a telescope eyepiece, an astronomer will shift the eye-patch from his or her dark-adapted viewing eye to the other eye, which has the added benefit of shielding the non-viewing eye from distracting stray light.
Although our eyes are capable of adjusting to an amazingly broad range of ambient light conditions, they cannot adjust to all of those conditions at the same time. This is, in part, why the images produced by the same laptop display can feel painfully bright when viewed from a dark room, yet disappear when viewed in direct sunlight. Unfortunately, the dynamic range of our vision is limited. Also, as ambient sunlight reflected by a display exceeds the light produced by that display, the displayed light seems to disappear. The keys to sunlight readability are for displays to be bright enough to be viewed by eyes that are adapted to sunlit ambient conditions and for display light to exceed the sunlight reflected by the display.
We can accommodate these varying lighting conditions by resorting to old-school technology, such as eye-patches, but would look more than a little silly. Better yet to deploy the right display technology for the lighting conditions.
Advantech offers a variety of sunlight-readable technologies, including touch-panel computers and industrial displays. The range of cost-effective sunlight-readable platforms that can be supplied by Advantech is greatly increased by its unique, in-house solution to enhanced LCD sunlight readability, a solution that requires no additional back-lighting cost, but instead uses an overlay that reduces reflected light by more than 98 percent. Simply put, the resulting improvement in sunlight readability is dramatic.