There are many rules in cycling. Unfortunately, most people have no idea what those rules are and they are subject to change or interpretation by just about anybody depending on the situation at the moment, as there is no governing body of "The Rules". Perhaps these nuggets will help!
You should never leave home without your eyewear. You should not make a habit of riding without eyewear, although approved extenuating circumstances include fog, overheating, and lighting condition. When not worn over the eyes, they should be neatly tucked into the vents of your helmet. If they don’t fit, buy a new helmet. In the meantime you can wear them backwards on the back of your head or carefully tuck them into your jersey pocket, making sure not to scratch them.
You shall not ride with earphones. Cycling is about getting outside and into the elements and you don’t need to be listening to Queen or Slayer in order to experience that. Immerse yourself in the rhythm and pain, not in whatever 80′s hair band you call “music”.
Truth in posting: I'm not making these rules up. They are poached.