Which of the following is the most common swelling of eyelids?: (A) Chalazion, (B) Neurofibromatosis, (C) Rodent ulcer, (D) Dermoid cyst
Answer is A. These are the most common lid swellings. A meibomian cyst is a chronic granulomatous inﬂammation  of a meibomian gland. It may occur on either upper or lower lids and presents as a smooth, painless  swelling. It can be felt by rolling the cyst on the tarsal plate.
Key Concept:
Meibomian cyst: They are epidermal cysts found on the free  edge  of  eyelid.  
Chronic Meibomian cyst is called chalazion.