In this case, the geomantic omen of ancestral graves is harmful to the eyes of grave owners and descendants. Trees cover graves with invisible eyes, and the most harmful to the eyes of future generations are thorny trees, such as jujube trees, locust trees and thorn trees.
The "thorns" of trees are the "nails" in the eyes, which will hurt the eyes. Therefore, the descendants of the feng shui tomb owner in this cemetery will have more eye diseases. If it is light, it will only hurt your eyes, and if it is serious, you will be blind.
If the root of the grave extends year after year, and the direction of extension happens to be the place with loose fertile soil, it may lead to the root of the grave. If so, future generations will not only have eye diseases, but also have great disasters.