The small particles under the eyes may be cornu rashes, sweat duct tumors or blepharocysts, which require further differential diagnosis. 1. Corns: Also known as white acne and fat grains, these are yellowish-white, solid pimples that can be seen on the eyelids, face, forehead, etc. They are asymptomatic and most of them fall off naturally over time. 2. Sweat duct tumor: it is a benign swelling that occurs in the ducts of sweat glands, and its condition progresses slowly. Eyelid sweat duct tumor is the most common type, which can be symmetrically appeared in the position of lower eyelid, and it can be a skin color, yellowish pimple or papule. 3. Blepharophalangeal cysts: chronic suppurative inflammatory diseases occurring in the blepharophalangeal glands, which can be caused by blockage of the outlet of the blepharophalangeal glands due to a variety of factors, manifested as a capricious small lump or pimple on the eyelid, which can be accompanied by symptoms such as foreign body sensation, blurred vision, etc. If there is no other abnormal manifestations, the eyelid may be affected by the symptoms. If there are no other abnormal manifestations, small particles under the eyes can be observed first, but any discomfort should be promptly consulted.