Eyes and Interest:

"A person’s eye movements and eye fixations correlate strongly with a person’s interest in, and attention to, things in their surroundings. People tend to look at what attracts them, especially at what they find curious, novel, or unanticipated."

"True, one can be attending to something, yet not looking directly at it; and one can look at something yet not be attending to it. Mainly, however, when we are in fact paying attention to things in our visual surround, the eye’s point-of-regard is a very good index of the distribution of that attention." 

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See also: Eyes: Knowledge for Managers

"Where our eyes look, at whom and for how long, is important for human sociality. Much knowledge has been accumulated on eye behaviour, mainly attention or 'gaze direction'. Eye contact can cut or caress – a dagger in dominance contests and a feather in social grooming."

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