Chalazion: A common, benign condition caused by a blocked oil gland in the eyelid, leading to a lump or swelling. It is often tender and may be accompanied by redness and inflammation.

Stye (Hordeolum): An acute, localized infection or inflammation of the eyelid margin, often caused by a bacterial infection. It presents as a painful, red lump on the eyelid.
Blepharitis: Inflammation of the eyelids, which can cause lumps, redness, and irritation. It may be associated with other conditions such as rosacea or seborrheic dermatitis.
Papilloma: A benign growth on the eyelid, often caused by a viral infection. It appears as a small, painless lump.
Cyst (e.g., sebaceous or epidermoid cyst): A benign, fluid-filled lump that can occur on the eyelid, often requiring surgical removal.

Basal Cell Carcinoma: A type of skin cancer that can present as a lump or sore on the eyelid. It is crucial to diagnose and treat early to prevent spread and complications.
Squamous Cell Carcinoma: Another type of skin cancer that can occur on the eyelid, often appearing as a firm, red lump.
Melanoma: A rare but aggressive type of skin cancer that can present as a new or changing mole on the eyelid. Early detection is critical for survival.

Keratoacanthoma: A rare, benign tumor that can occur on the eyelid, often resembling a small, dome-shaped lump.
Xanthelasma: A rare condition characterized by the accumulation of fat under the skin, leading to yellowish lumps on the eyelids.
Amyloidosis: A rare condition in which abnormal proteins (amyloid) accumulate in various tissues, including the eyelids, leading to lumps or swelling.
Lacrimal gland tumor: A rare tumor that can occur in the lacrimal gland, located under the eyebrow bone, and may present as a lump on the upper eyelid.