Eyebright, Euphrasia officinalis is a semiparasitic plant with roots that attach to some grasses. Eyebright herb is often used in a poultice. Because of its parasitic nature, the USDA has banned the import and sale of any eyebright products that may contain viable seeds. This means that imported eyebright products can still be sold in powder form, as an extract or tincture or in capsules but not in whole or cut form.