"Good eye contact" is an important part of great communication. But how much is too much? When used correctly, direct eye contact can show a person is confident and attentive but too much can make them seem creepy or intimidating.
I remember listening to a speaker at a conference and going up to them after their lecture to ask a question. Big mistake. My question was met with an informative answer but also a relentless fixation of gaze that was uncomfortable to say the least. If you have ever felt a little freaked out by another person staring you down, you're not alone.
According to frequently referenced studies by Argyle and Dean, direct eye contact should typically last somewhere between 3 and 10 seconds before one or both of the parties briefly look away. If eye contact is held longer than 10 seconds, it may be misinterpreted as flirtatious or aggressive.
Also, different cultures interpret eye contact in different ways. Read the situation and use the other person's behavior as feedback to determine how much eye contact to give. Do what feels comfortable for you and what seems to be most comfortable for the other person.
More isn't necessarily better.
A version of the article was previously published by myself here.