Let’s say it’s twenty years in the future, and everyone, to borrow a phrase from Verner Vinge, is wearing. That is, we all have our cyber-contact lenses, and we take for granted that we will all have augmented reality floating in the air between us.
Suppose you and I want to discuss some text. If the text document just floats in the air between us, then either (1) we each see the document the right way forward, or (2) one of us will see it backwards. The problem with the first scenario is that if I point to (or look at) some part of the document, the place where I’m looking won’t correspond to what you see there.
In 1989 Hiroshi Ishii dealt with a similar issue very cleverly in his “ClearBoard” interface. People interacted face to face through a video screen. The video flipped everybody’s image left/right, so that you always saw the other person in mirror reverse. This meant that we could both look at the same document floating between us, and everything worked out — text was forward for both of us, and our gaze directions always matched.
But you can’t do that if you’re physically face to face with somebody. One possibility is that people will just learn to read backwards, but somehow I doubt that this will catch on — from a social perspective, the situation is just too asymmetric.
Another possibility is that augmented reality will use a convention that text runs vertically, rather than horizontally. We can already read vertical text just fine, so this won’t require any new skills or training. The left right reversal will take place within each character. For example, we will both see the letter “E” rather than one of us seeing the letter “∃“.
In this arrangement, one of us might find ourselves reading the vertical columns of a document from right to left, rather than from left to right. But that doesn’t seem like a real obstacle to comprehension. To make it clear whether you’re reading left to right or right to left, the text in each column could be either left justified or right justified. Below is an example of the same text, as seen by two people who are face to face with each other: