As the Prophet ﷺ said, "The truffle is a form of manna, and its juice is a healing for the eye." It grows in the ground without being sown, and is found in the Sahara. There are other mushrooms that are effective for vision, such as shiitake, reishi, and maitake.
They can be found in capsule form, for example. Arab physicians cite eyebright, which has astringent properties due to the presence of tannin, as well as anti-inflammatory properties conferred by iridoids. It also contains flavonoids. It is found in the form of an eye drop or a capsule, and must be taken over several months to obtain results. In addition, the blueberry, which is an antioxidant, is also effective for eyesight.