A stye, medically known as a hordeolum, is a common and usually painful infection that appears as a red, pus-filled lump on the edge of the eyelid. This localized inflammation occurs when one of the small oil glands or an eyelash follicle becomes blocked and subsequently infected with bacteria. The infection most frequently involves Staphylococcus aureus, a bacterium commonly present on human skin. While this condition is generally harmless and resolves on its own, concern often arises regarding its potential to spread to the other, healthy eye.
The Risk of Spreading a Stye to the Other Eye
While a stye is a confined infection, the bacteria causing it can be transferred to the unaffected eye, a process known as self-inoculation. The primary mechanism for this transmission is physical contact, where a person touches the stye and then immediately touches their other eye without washing their hands. This action moves the Staphylococcus bacteria directly to the new site, potentially causing a new blockage and subsequent infection.
The bacteria can also be spread through contaminated objects that come into contact with both eyes, acting as fomites. Using the same washcloth to clean both eyes, or sleeping on a pillowcase that has discharge from the stye, can facilitate the transfer of the bacterial load. This physical movement of the infectious agent creates a new instance of the infection. This self-spread is the most common reason a person might develop a stye in the second eye shortly after the first.
Essential Hygiene Measures to Stop Transmission
Preventing the spread of the stye-causing bacteria requires strict personal hygiene, especially around the eyes. Avoid touching or rubbing the infected eye. If the eye must be touched, such as when applying a warm compress, hands must be washed thoroughly with soap and water for a minimum of 20 seconds immediately before and after.
Towels and washcloths used on the face should be separate from those used by others in the household. A fresh, clean cloth should be used for each warm compress application, and these items should be laundered in hot water to eliminate contamination. Furthermore, a person with a stye should temporarily stop wearing eye makeup, including mascara and eyeliner, as these products can easily harbor and transfer bacteria.
Any eye makeup used while the stye was present should be discarded immediately, as the product is likely contaminated. For contact lens wearers, switch to glasses until the stye has completely healed to prevent bacteria from adhering to the lens and being reintroduced into the eye.
Clarifying Stye Contagion: Bacteria vs. Virus
Styes are caused by a localized bacterial infection, involving the Staphylococcus species, which naturally lives on the skin. While the bacteria can be shared, the infection is not considered highly contagious like a common cold or a viral infection. The bacteria must find a blocked oil gland or hair follicle to establish the infection, which is not guaranteed by casual contact.
This differs significantly from highly contagious conditions like viral conjunctivitis, commonly known as “pink eye.” Viral eye infections spread easily through airborne droplets and casual contact, leading to rapid transmission. A stye, conversely, represents a contained abscess of pus and bacteria. The risk of spreading it to other people is low, unless they directly contact the drainage from the stye and then rub their own eyes.