In a presentation, making eye contact is one of the most important things you can do. It will help you win business.
Even if using PowerPoint, your eyes should be on the audience, not on the screen. Have a laptop at the podium or on a table so you can refer to it while facing the audience, instead of constantly looking over your shoulder.
But, even with that, it is for reference only. Hopefully, you know your presentation well enough that you don’t have to read it word for word.