Some companies have developed transparent displays to the point where they may be the immeidate future of head-mounted, heads-up and state-of-the-art shopfront technology. A new analysis has shown that their market may be worth US$2.591 billion by 2023. This market will be made up of see-through OLEDs and LCDs in a range of display sizes.
https://www.notebookcheck.net/The-transparent-display-market-could-be-worth-over-US-2-billion-in-4-years.413858.0.html