I have had on both eyes and upper and lower. My eye Doctor says if You can catch them early putting hot washcloths on the area for 20mins 4 times a day til gone. I have had to have many surgeries to have the removed. It kills having that scratch feeling that some thing is in Your eye. I just wish there was a wayvnot to get them. He said nothing can be done , but wondering if any one eles has found out more ? What causes them ?