They say that the eyes are the "windows to the soul," making eye contact the best way to connect with others. You've seen how this works many times, whether you're in the halls, in a classroom, or eating with friends. As simple as it would seem to look someone else in the eye, using the wrong amount of eye contact would be akin to playing a piano that is badly out of tune. Even though you are playing all the right notes (or saying all the right things), something just doesn't feel right to the listener.

Optimal Length of Time

Marty Brounstein, author of "Communicating Effectively for Dummies," argues that there is no magical formula for determining the optimal length of time for eye contact -- it depends on the situation and person. That cute guy in Chemistry you like might welcome a lengthy glance from you. However, Brounstein does note that in one-on-one situations, eye contact that lasts from 6 to 20 seconds is generally the most comfortable. When it comes to group situations, it is best to shift your gaze more frequently -- usually every 3 to 6 seconds -- so that you have a chance to connect with everyone. Likely, you've seen how this works at every party you've been to -- but you were probably too busy exchanging this all-important eye contact to notice the dynamics behind it.

Situational Demands

The more familiar or comfortable you are with someone, advises Brounstein, the longer eye contact will be. If there is actual chemistry between you and that cute guy, your gazes will probably last longer. Sharon Sayler, author of "What Your Body Says (And How to Master the Message) concurs, adding that you should watch for "cues" from your conversation partner as to how much eye contact is appropriate. A study published in the March 2013 issue of the journal "Plos One" showed that prolonged eye contact elicits feelings of arousal in conversation partners -- which can be a good thing with your new boyfriend but bad with guys in class you barely know. Modify how long you look at someone, depending on whether you know them well or not.

Cultures Differ

How long you make eye contact can also depend on the cultural background of your conversational partner. The same study in "Plos One" found that if you are from an Eastern culture, you are more likely to perceive eye contact as aggressive and threatening than if you are from a Western culture. Sayler agrees, saying that in Western cultures, eye contact with a superior is a "sign of respect" while in Eastern cultures the opposite is true -- and that in general, eye contact is more common in the West. If you and your new boyfriend are from different cultural backgrounds, one or both of you might need to adjust your level of eye contact to make the other comfortable.

Gender Matters

Sayler adds that you may also wish to take the gender of your conversation partner into account. Girls are used to more eye contact than guys, and some guys even consider too much eye contact to be confrontational -- particularly, if it is from another male. The next time you are at a party, have a look around to see how this plays out -- you will probably notice that the amount of eye contact used by your friends depends on whether they are male or female.

Just Right

Too little eye contact can also be a problem according to Sayler. If you avert your eyes, others may assume that you are either lying or lacking self-confidence -- both of which will make them less likely to talk to you. Strike a balance by offering enough eye contact to make your classmates and friends feel comfortable and convey the image that you are confident and truthful.