Hi Doctor, I am 39 year old male. It usually happens while driving..... after 5 to 10 minutes of drive, my eyes starts getting heavy and I feel lot of pressure on my forehead. And its the same kind of feeling when you are very tired and only want to go to bed for a sound sleep. I try to remain attentive by taking some some fluids or eat something, but usually it becomes so severe that it even makes it difficult for me to remain my eyes open. This feeling is only while I drive, at the end of the drive these 'feelings' are also gone. Can you explain why this happens and how can i overcome this situation?

Thanks and regards.