There is a popular condition called Meibomian gland Disorder where the glands that produce oil in your eyes get dried up or get clogged. Either of these reasons would cause you to have the above symptoms. When
Additionally, the inherited genetic allergies to proteins, carbohydrates, lipids and several essential aminoacids (e.g., Phenylalanine; glutamic acid etc.) are very much prevalent in all human populations thus depriving them from many food items. Needless to say, the list of chemical compounds ...