As a communication specialist, I can tell you how to craft compelling presentations, share powerful stories, and build brand messages. All that work is worthless if you violate one cardinal rule of body language: making eye contact. The art of eye contact is an art worth studying.

Like it or not, people will judge you and your message based largely on eye contact. In one study, investors watching CEOs give their IPO roadshow presentations formed impressions of the CEO very quickly--in as little as 30 seconds. Their perceptions were based largely on non-verbal impressions, most notably, "eye gaze."

Study after study confirms the importance of eye contact in business environments. According to a survey of recruiting professionals, 68 percent said "avoiding eye contact" is one of the biggest mistakes job candidates make.

These four tips will help you achieve the right amount of eye contact in nearly every business interaction:

1. Keep your eyes on your listeners.

The main reason I recommend rehearsing your presentation is so you can avoid reading from notes. In the CEO roadshow study I cited above, the CEOs who made the worst impression were those who read their presentation word for word from either the slides or their presentation notes.

Slides provide information. Your eye contact creates trust. 

You can certainly glance at notes from time to time. We all do. It's perfectly acceptable. Just be sure to make eye contact with your audience when you're delivering the information.

In a networking event, keeping your eyes on your listeners means exactly that--maintain eye contact with the person you're speaking to. Give them your full attention. Wandering eyes is a sure-fire way to break a connection with another person--on a date or in a sales pitch!

2. Turn your body toward your audience.

I'm a proponent of creating visual slides because text-heavy slides are easy to read from. Too many speakers turn their entire body toward the slides and read them out loud, or they address the slide instead of the audience. That's a no-no.

Keep your abdomen pointed toward your listener, and your eyes will follow. When someone from one corner of the room or the opposite end of the table asks a question, turn your body toward that person. It's a non-verbal signal that you're giving them your full attention.

3. Roam the room when you can.

This is an advanced engagement strategy for large audiences. It takes courage and it requires practice. If you can do it, your presence will be magnified significantly.

Since eye contact is so important, walk away from the podium or stage to get closer to your audience. Look at individuals in the eye while you're addressing a particular topic. Then, look at someone else to address the next point or sentence.

Watch Salesforce CEO, Marc Benioff, work the room during his DreamForce conventions. He doesn't stand behind a lectern. He's close enough to the people in his audience that he looks like he's carrying on a conversation, not giving a presentation.

4. Maintain eye gaze for three seconds.

The most common question about eye contact is, "How long should I look at someone in the eye?"

It's a tough question. Cultural differences are real and come into play. What's appropriate in some cultures might come across as too dominant in another. I recommend reading up on cultural differences when visiting foreign countries. 

In most Western cultures, the three-second rule seems to be a good guideline. According to Quantified Communications, a company that analyzes videos of speakers, the "sweet spot" for holding eye contact with an audience member is about three seconds. According to their research, direct eye contact that is held for more than 10 seconds is "unnerving."

Remember tip No. 3? When you're roaming the audience with your eyes, lock your eyes with an audience member for three seconds, then move on.

Shark Tank investor and real estate entrepreneur Barbara Corcoran says she pays attention to body language when sizing up entrepreneurs who pitch their ideas on the show. Specifically, she pays attention to their eyes, according to one interview. "If someone's not looking at you in the eye, believe me, you're not trusting them," Corcoran says.

Corcoran's right. First impressions are hard-wired in our brain. Our ancestors had seconds to decide whether someone was friend or foe. If you're perceived as untrustworthy, you'll lose the opportunity to make a sale, win a project, or get a date with the person of your dreams.

The eyes are windows to the soul, and the best way to make a positive first impression.