Soft Contact Lens Complications Practice Test

Short-term metabolic responses of the corneal epithelium to contact lens wear are mainly driven by tear-film disruption and reduced oxygen, leading to surface damage and swelling. Erosions are breaches of the epithelial surface from dryness or mechanical irritation, reflecting immediate injury. Edema is fluid buildup in the epithelial layers due to altered tear exchange and hypoxic stress, another direct short-term metabolic reaction. Warpage represents a temporary mechanical distortion of the corneal shape caused by the lens pressing on the cornea, a structural change rather than a metabolic one. Microcysts, however, are tiny cystic spaces within epithelial cells that arise from longer-term metabolic disturbances and sustained edema, so they do not fit the pattern of a short-term epithelial metabolic effect.