Hordeola and Chalazia look the same to me. How can I differentiate?

Question

Please don't tell me to see a doctor, this is an academic question. Can it be relied on that the stye (hordeolum) is painful and the chalazion isn't?

Answer 1

A hordeolum is more commonly known as a stye and is an infection of the hair follicle at the base of the eyelash. Thus it appears at the lid margin. It can affect the upper or lower eyelid.

A chalazion is sometimes called an internal stye, and is an infection of one of the several meibomian glands in the inner surface of the eyelid. The glands secrete a waxy substance that lubricatesthe lids. A chalazion causes a lump on the eyelid that may be uncomfortable or even painful. It takes much longer to resolve than a stye. Usually the upper lid is involved, but occasionally one appears on the lower lid.

Chalazia and hordeola are rarely serious, but are a source of discomfort, sometimes pain, and are cosmetically unappealing, at least transiently.

Answer 2

They seem the same because they are. The difference is that the former is acute and the latter is of longer standing.