A healthy cornea has numerous mechanisms that prevent the possible capture of microorganisms and development of infection – thus it has a bacteriostatic (bacteria-killing) effect.
These mechanisms include:
- The cleaning ability of tears
- Bacteriostatic components of the tear film, such as the enzyme lysozyme, or secretory immunoglobulin A
If the corneal epithelium is not impaired and the above mechanisms are not disrupted, then most bacteria are not able to infect the cornea.