The white string is a peculiar tale told by parents so their children wouldn't attempt to pierce their own ears.
A young girl desperately wanted to get her ears pierced however her parents though she was too young to do so, eventually they caved in. they gave the girl some money and told her to go to the local jeweler, however the girl thought it a waste to spend money when she could do it herself so, pocketing the money she called over her best friend who helped her pierce her ears with a needle.
After a few day the girls ear became itchy so she went to the bathroom and she saw a white string poking from her ear so she pulled and pulled it but to no avail it didn't end so she pulled a pair of safety scissors from her bag and cut it, then everything went dark. When she came too she couldn't see anything but heard a voice who identified itself as a doctor then said "i'm sorry to report but what you cut was your optic nerve and it's likely you'll never see again".