Eye contact is a form of communication. However, there is supposed to be a shared language between two people when eye contact is made. A person should be able to read what the other person is thinking and feeling. That is the way nonautistic eye contact works. On the spectrum, that is usually not the case.

First, eye contact is not something, that is natural or even desirable to us. We have a problem with the interpretation of this language. There are many reasons why we cannot share the language. First, looking at someone's eyes is very uncomfortable. As a friend of mine on the spectrum says, it is like looking into the headlights of a train. Eyes flicker and move, which is uncomfortable for people on the spectrum. Even if we do make eye contact, we don't know the unspoken language. We have to learn each thing that the eyes tell us, from very obvious to very subtle.
The next problem is in what we send. I have no idea about what messages I am sending with my eyes. That causes confusion for the person who is trying to read me, because I do not send obvious messages. With that confusion on both sides, communication using this medium does not work very well. The big deal about this whole eye contact thing is that our society has built in a lot of meaning into the use of eye contact. We have interpreted this as a sign of honesty and not hiding something, being comfortable, and the art of listening.

These are the expectations that are put on everybody in this society, whether we can make eye contact or not. If you do not use it, you are accused of lying, not being comfortable, having something to hide, not listening, etc. This does not make sense when one is on the spectrum. I have yet to meet people on the spectrum who are natural liars. Some of us have had to learn to be devious when we have to be and tell the little white lies, so that we do not hurt the feelings of nonautistic people. Bluntness has never killed anybody. We lie only when we must and it is not very natural to us. Therefore, thinking that we lie because of not having eye contact makes no sense.
Eye contact has nothing to do with listening. The eyes and the ears are not connected on the same band. I can hear and learn without having to really look at someone. There is also peripheral vision, which is looking but of the sides of the eyes. Nonautistic people think that if the eye contact is not full in the face, it is not eye contact. I can be comfortable and not give eye contact. In fact, I am less comfortable if I have to give it all of the time. It is stressful and takes away from my self-ease. In fact, if I meet someone that I do not know, I do not give eye contact. I cannot stress myself to give eye contact and have a conversation at the same time.

This is not possible for me if I am using all of my energy to make eye contact. I am not very happy about the emphasis put on making children on the spectrum do eye contact against their will. It is a very stressful thing and almost like torture (for reasons that I have given earlier) for children and adults. To me, eye contact is for the benefit of nonautistic people and not much of a benefit for us on the spectrum. We cannot do it very well, nor communicate it very well. It also stresses us and makes us uncomfortable. There is no need to put those kinds of stressors on us.