It is indeed true. Too much extentions will damage your eyes. The skin align eyes, our eye balls tissues and our eyelases are all very delicate and subtle. They are easy to get irritated and allergic. There are many materials for eyelases extensions for you to choose, plastic, human hair, silk or mink, it always irritate our eyes. It needs some kind of adhensive subtance to stick the extension onto your eyelashes. This kind of adhensive subtance is chemical material which could be an irritant too. Some people develops red and bloodshots in the white of eyes, and has a strong foreign body sensation. It could also cause eyelashes fallen out. Anyway, it is not very good for eyes. If you still want to do it, choose the light material. The lighter, the better, the less damages to eyes.