Styes can form on the outside (external) or inside (internal) of your eyelid. External styes are more common than internal styes. Most external styes start in an eyelash follicle, but may also ...

and so an infected meibomian gland causes an internal stye. External styes are the result of an infection and/or blockage of ...

Source: Focus Medica. A small red, painful lump in the edge of the eyelid. Stye is usually caused by bacterial infection. It may be present inside or outside the eyelid on one or both eyes and is ...