In short, no, it's not okay.
Remember to never read your slides to your audience. For starters, the audience can read a slide much faster than you can read it aloud. And more importantly, you want the audience to pay attention to the words you speak, which should be far more interesting, eloquent, delicious, thoughtful, and red-hot! than what you place on any slide. Each slide should contain just enough information to highlight the major points and support what you say.
I recall a workshop I once attended where the facilitator stood at the front of the room and read material verbatim from the handout she had provided. I wanted to scream. I walked away having learned nothing I could not have read on my own.
When a presenter looks up at the projection screen to reference the material or to read it to the audience as opposed to looking at his/her laptop or computer, it's akin to ...
... the teacher constantly looking over a student's shoulder to reference his textbook while lecturing or conducting a face-to-face class instead of the teacher looking at her own book. If that happened over and over, the student would eventually say (or want to say) "Didn't you bring your own book?! Stop looking at mine!"
Or it is similar to the salesperson who gives you a brochure and constantly wants to look at the one he gave you and turn the pages in it instead of using his own brochure to reference and discuss a product with you or, better yet, already knowing his material well enough to discuss without looking at a brochure. (And read number 5 at this link to find out how to become comfortably and intimately familiar with your content.)
When you turn to read from the projected slides or constantly reference them as opposed to referencing your personal materials, the audience is subconsciously thinking "Why are you looking at that? It's for MY eyes!"
Try your very best to avoid looking at the slides that are projected on the screen when you present, and never address your audience with your back turned to it. I write "try your very best" because it is completely natural to catch yourself glancing at the projection. Instead, position your laptop or computer so you can easily look at its screen, which is projecting the same thing your audience sees; I also recommend putting your presentation in presentation view so you can see your notes along with your slides while the audience sees only the slides and not the notes. If nothing else, have your slides notes printed or written out and next to your laptop or other presentation materials so they are easily accessible.
The projected slides are for the audience's benefit, not the presenter's; as such in addition to thoughtful presentation design, for a polished professional look to your delivery, glance at your laptop or computer screen when you need to reference the material on which you are presenting, not the projected slides.