Chalazion
Also called meibomian cyst, chalazion is caused by clogging of the meibomian gland by sebum. The location of chalazion could be anywhere, from inside of the eye to the eyelids. Apart from a red bump, other symptoms of chalazion include painful, itchy, and swollen eyelids. This type of bump is not dangerous to health. However, despite the medication, it might take some time to get completely cured.