We should always think about keeping a neutral spine in exercises like the squat & deadlift, and sometimes just changing our head / eye position can make a big difference.
Everyone will be different. Some people might need to look down more then others, some people might need their chin tucked more then others and so on. A good start point for eye level is usually looking down at where the floor meets the wall.
We want a nice neutral spine from the neck lol the way down. And were we go through a quick demonstrations, check it out!