To limit the probability that persons will not be familiar with the existence or position of glass or transparent doors, which could lead to persons hitting or bumping into such doors, which could lead to harm to persons.
To limit the probability that persons will not be familiar with the existence of glass or transparent doors, which could lead to confusion in accessing an exit in an emergency situation, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.