What effect does long-term hypoxia have on the cornea?

Long-term hypoxia, which refers to a deficiency in the amount of oxygen reaching the tissues, particularly affects the cornea due to its avascular nature. In a hypoxic environment, the cornea struggles to maintain homeostasis and its normal physiological functions. One significant consequence of extended hypoxic conditions is the development of microcysts within the corneal epithelium.

Microcysts are small, fluid-filled spaces that can form in response to the stress of inadequate oxygen supply. They are a manifestation of the cornea's attempt to adapt to low oxygen levels, as the epithelial cells can swell and become compromised under such circumstances. This condition can lead to a variety of visual disturbances and discomfort for the contact lens wearer.

The other options do not accurately reflect the pathological changes and visual outcomes associated with long-term hypoxia in the cornea. The corneal epithelium does not strengthen under hypoxia; rather, it can become less effective at serving as a barrier and maintain its integrity. Improved corneal shape and enhanced vision are also unlikely outcomes of prolonged oxygen deprivation, as hypoxia generally leads to complications rather than benefits.