So there's this book I read maybe 5 or 6 years ago that I absolutely loved but never finished the series and I can't remember the name and can't find it. From what I remember there are these hidden towns built around these magic trees and they're really dependent on the trees to survive. If the trees are burned, and the ashes get in ones eyes, they get stronger for a while and get glimpses of the future but are their eyes turned white and normal people are blinded. People that this happen to get kicked out of these villages and some start a legion that burn the trees from other villages. The main character finds the sapling of one of these trees and has to travel to one of the villages to give it to them. Anyone know what book it is?
Could this by any chance be Dormia?
"Oh come now, my friend," replied the doctor. "I've been a sage of medicine in this town for a good many years--as have my grandfathers and great-grandfathers before me--and there is only one thing that causes the pupils to disappear entirely: purple ash. One major side effect is whiteness of the eyes and blindness. Other, more desired effects are telescopic vision and a moment of clairvoyance in which you see into the future. Does any of this ring a bell? Yes, I suspect it does. The curious thing is how two travelers like you got your hands on purple ash. The only people who ever have purple as are the Dragoonya. They use it and their eyesight suffers. Almost all who use it go entirely blind."