Women’s hats for big heads
With cute ponytail caps, you're able to look stylish while keeping the sun out of your eyes. Their innovative design also keeps the hair off your neck and out of the way. ... Simply loosen the bun after you do your hair to give it a casual yet controlled look

The purpose of these are to keep your head cool provide ventilation. They can be holes in the fabric, bordered by a sewn edge, or they can be punched with small metal rivets Eyelets help with ventilation.