- If your eyes signal that your talk's off-track: Those quick, inadvertent looks to one side or the other (or up and to angle) happen at the same points that you might otherwise use a verbal "um" -- the points where you've forgotten where you are heading or what words come next. (Here's a picture of a very brief visual um from Stephanie's video of yesterday.) You're trying to mark your place, remember and regroup, but a glance to one side doesn't leave you enough time. Instead of these "visual ums," I recommend you practice some verbal time-buying phrases to build in a little more time to recall what you need to say.
- If your eyes avoid acknowledging your audience--all of the audience: If you avoid looking at audience members, they'll feel as if you are avoiding them, when you really want to connect with them. You don't need to look at everyone, just enough people throughout the course of your talk that they know you are engaging with them. If you've heard or been taught that direct eye contat is disrespectful, that's true--but only in certain cultures. Here's a Wikipedia article with more background on that issue. In most cases, however, the audience will consider it disrespectful if you don't acknowledge them with your eyes.
- If it makes you uncomfortable: This doesn't mean you can avoid it, but anything that makes a speaker uncomfortable is worth analyzing. Some speakers like looking at their friends' smiling faces to boost their confidence; some avoid looking at their friends and find it easier to make eye contact with audience members they don't know. You'll have to find out which works for you. Practice looking at sections of the room--front, back, and each side--throughout your talk, as well as at some individuals. Smile and engage with individuals from time to time, and develop your confidence as you go.
Finally, lack of eye contact often signals your discomfort and lack of confidence with public speaking. Want to practice getting more confident with eye contact? Practice on video or webcam--a lot of my trainees say video practice helps them with both confidence and with focusing their eye contact. (And you can use it to check whether you look down, away or use visual ums, then go back and practice how to get past those moments.) Please leave your questions or comments about eye contact in the comments, as well as any tips for Stephanie!