If the eyes are the windows to the soul, then soulmates can never stop looking at one another. Their souls know how to communicate silently and completely in a language only the 2 souls can comprehend.

Neither soul ever looks down on the other, nor does he or she look up to the other (unless of course the soul lesson is one of equality) soulmates are always equal, at the same level of understanding.

The connection is always instantaneous, no explanations required and no amount of analysis will ever be able to explain why this happens.