It is a disease caused by the infection of human papilloma virus. The external symptoms are the sudden appearance of brown, or near-skin colored, protrusions on the eye, and the surface is rough and hard to the touch, and the boundaries are usually very clear. However, there are two types of fatty grains, the first is called sweat duct tumor and the second is called cornea. It is very easy to distinguish cornea from lichen planus because cornea is a raised, pointed and rounded bumps around the eyes that can have small keratinous balls squeezed out of them. In some cases, sweat duct tumors may be similar to flat warts, but they do not occur suddenly, they can appear at puberty and are adenomas arising from the terminal ducts of small sweat glands. They are usually found in females and are distributed around the eyes as a hemispherical bulge high above the skin, which is soft to the touch, not rough, and close to the skin color.