Styes are not detrimental to the eyes or to eyesight. Pain will occur, followed by a swelling or redness. The eye area will also be tender to the touch. Some stye sufferers find that the whole eye area becomes swollen, while for others, only the infected area swells. The eye may also tend to water and become blurry.

Styes are caused by Staphylococcal bacteria. This type of bacteria can usually be found in the nasal passages and is easily passed to the eye. Staphylococcal is passed by rubbing the nose and then touching the eye area. The gland situated at the end of eyelid may then become infected.