Pupils Dilate Due to Emotional States

http://www.scientificamerican.com/article.cfm?id=eye-opener-why-do-pupils-dialate

The visual cortex assembles the images we see, but the autonomic nervous system manages pupil size among other involuntary bodily functions.  It is well known that pupils respond to light, but they also respond to emotional states, so much in fact, that researchers use pupillometry to investigate psychological phenomena. By controlling light sources and using infrared cameras scientists are able to track changes in one's emotional states simply by the dilation or contraction of their pupils. For instance when you solve math problems the more complicated they are the more your pupils will dilate in response. Researchers could also glean when a subject had given up on the problem based off of pupil contraction. Other research suggests that people who are more intelligent (based off of Scholastic Aptitude Test Scores) display less pupil dilation when confronted with cognitive tasks when compared to their lower scoring counterparts, indicating a more efficient use of brain power. Some researchers even say that pupillometry can betray someone's decision before it is openly revealed. When asked to press a button anytime in a ten second span pupil dilation often occurs one second before they press the button and peaks two seconds afterwards. However, because it is nearly impossible to control any contributing factors to pupil dilation and contraction outside of a lab environment it is dubious that pupillomentry could be exploited for practice in real life.

I think this is all very cool. It's interesting that scientists were able to find a link between intelligence and pupil dilation in cognitive tasks. But It makes me wonder if pupillometry could ever be effectively used outside of the lab. What d you think of this? Based on the article do you think that people will ever be able to exploit this for their own purposes outside of a lab setting ( like the Canadian government trued to do with the "Fruit Machine")? In what ways do you think this could be used to benefit society? Likewise, what ways do you think that pupillometry could be abused? Do you think we'll ever definitely be able to say why our pupils give away our emotinal states?