The use of contact lenses is huge nowadays, almost everybody wears them without anybody noticing, however i do not believe that contacts are the safest choice when it comes to protection. Yes, contacts will protect your eyes to some degree, but when dust and ash gets in the way, that person's eyesight is going to get really blurry. My opinion is, workers should wear safety goggles at all times, of course, it depends on the task, but for the most part, goggles are the safest option.