Gang members and spectacles

Have you ever noticed that you don’t see gang members with glasses (spectacles)? Do you think part of the initiation into a gang involves a vision test? Somehow I cannot believe that the general level of hygiene and self care allows for the wide spread use of contact lenses within gangs. Does that mean there a lot of gang members out there involved in nefarious activities not being able to actually see what they are doing? Seems to me this would be a great starting point  for any defence lawyer