It is very common for children to have gray patches in the white of their eyes, especially in preschoolers. These patches are called scleral blackening, and their form is diverse, some are large, some are small, and some appear in multiple places, but they are generally unrelated because the sclera is thin and the black-brown color of the inner layer of the uvea is seen through, which does not affect vision. As we grow older, the sclera will thicken and many plaques will gradually disappear or fade away. If there is significant color deepening or bulging of the patch and there is significant vision loss, beware of the presence of uveitis or other malignant changes.