I understand the events in the time line that made river tale and Riverfell..rivers.but why does everyone have those lines going up and down from their eyes like gaster?
seen from Indonesia

seen from Italy
seen from United States
seen from United States
seen from Ukraine
seen from Russia
seen from United Kingdom

seen from United States
seen from United States
seen from Ukraine
seen from China

seen from Italy
seen from United States
seen from China
seen from Canada

seen from United States
seen from Netherlands
seen from Germany

seen from United States
seen from China
I understand the events in the time line that made river tale and Riverfell..rivers.but why does everyone have those lines going up and down from their eyes like gaster?