If you stare at the slides while talking, the audience will also tend to do so. If you continuously look at the slides, you will eventually become a kind of radio.

Only look at the slides when you specifically want the audience to look at them and nowhere else. If you need to know what is on the slides, take a glimpse at your monitor. Of course, you first have to make sure that the monitor is in front of you, and close enough so that you can see it without really looking at it.