As long as we don’t know where each individual eye is looking, a reticle may appear to be in two places at once, or one view of the reticle may be suppressed.
In some cases this may be acceptable, when the user has the option to close one eye of their choice and position the reticle to make a simple selection. Otherwise, a reticle is only a viable choice of input *after* we have achieved fusion between the eyes.
