Round, painless swellings on the upper or lower eyelids caused by obstruction of the meibomian glands, which are supposed to lubricate the eyelids. They can occur at any age and are common in those suffering from skin conditions such as acne, rosacea or seborrhoeic dermatitis.
The cyst may become infected and this leads to more swollen, painful, red eyelids. A blurring of vision can occur due to the large swelling which can put pressure on the cornea. Larger cysts may need surgical removal, though 1 in 3 cysts disappear without treatment.