Eyelid cysts are very common in clinical practice and are swellings that protrude from the skin surface and have a heterogeneous texture. There are many causes and diseases that can cause eyelid cysts. Some of the common ones are lid cysts, mydriasis, and eyelid swellings. A lid cyst is caused by an obstruction of the lid gland due to the deposition of lipids and other metabolites in the lid gland, and may have localized redness, swelling, and hard nodules. A lid cyst is caused by an infectious inflammation and may have localized redness, swelling, and pressure pain. In some cases, the nature and cause of the lesion are not clear, and some require further ancillary testing, such as ultrasound, superficial tissue ultrasound, orbital CT, orbital MRI, etc. If the nature of the lesion cannot be confirmed by these tests, surgical excision and pathological examination is required to clarify the nature of the lesion. For example, tumors, lipomas, and hemangiomas that occur in the eyelid. Eyelid cysts can also be caused by allergic factors, such as certain allergens that can cause edema of the local tissues of the eyelid. Therefore, the diagnosis of eyelid cysts requires a combination of clinical manifestations, relevant ancillary tests, and even pathologic examinations to clarify.