How can you tell difference between a sty and pink eye?

Here's how: In conjunctivitis, or pink eye, the whites of the eye get more red or injected. With styes, or chalazion, the eyelid is also affected.

They're different: A stye is within the eyelid. Pink eye affects the surface of the eyeball.

Infections: A stye is a clogged oil gland that is infected. The body typically walls it off as a red painful bump around the eyelid skin. Pink eye is a conjunctivitis or an infection causing a red eyeball that can be very contagious (viral). Pink eye can easily travel to the other eye, whereas it is less common with styes.

Eye vs eyelid: Pink eye is a viral or bacterial infection of the surface of the eye and mucus membranes lining the eyelids (conjunctiva). A stye is an infected eyelash follicle and presents as a red, painful bump on the eyelid.