As labor intensifies, it is important to build your Birth Nest. That is a place that is physically comfortable and doesn't interfere with your focus and coping. Some interferences are harder to avoid than others - like the sun. An eye mask helps you keep your Birth Nest dark and safe.
These also help you bring your Birth Nest with you if you are travelling to your birth location, like a hospital. If your visual surroundings can stay the same, your internal focus has less to compete with.
I love these because the silky fabric is so luxurious, and they are big enough and well-padded to really block out the light and stay on your face.