What typically causes microcysts in the cornea?

Microcysts in the cornea are most commonly associated with a lack of oxygen, particularly in cases of long-term hypoxia. When the cornea does not receive sufficient oxygen, especially during contact lens wear, it can lead to the formation of microcysts. These microcysts are small fluid-filled pockets that develop in the epithelial layer of the cornea as a response to reduced oxygen supply. This condition is particularly prevalent with certain types of contact lenses, especially when they are worn continuously or for extended periods without proper breaks.

The other factors listed, while potentially contributing to ocular discomfort or corneal health issues, do not directly cause the formation of microcysts. For instance, inadequate eyelid closure might lead to dryness or irritation but is not specifically linked to microcyst formation. Similarly, excessive lens movement can result in mechanical irritation but does not inherently create microcysts. Allergic reactions may produce symptoms that affect vision or eye comfort but do not lead to the specific condition of microcysts in the cornea.