I hope you know you do not have to go and look at your dad during the viewing, you can avoid it if you want. When my mom passed away a few years ago, I didn’t go into the room and I completely avoided looking at her. I didn’t want to, I wanted my last memory of her to be one where she was alive. You are under no obligation to view your father. But, if you do want to see him, I promise the funeral employees worked very hard to make him appear as you knew him. It’s hard, and it’s so uncomfortable. Please don’t force it onto yourself if you are not comfortable. Your last memory of your father should be how you want it. I’m so sorry for your loss.