Which of the following are complications of contact lens overwear?

Contact lens overwear syndrome describes a pathological state where extended use exceeds the physiological tolerance of the corneal epithelium. The cornea lacks a direct vascular supply and relies on atmospheric oxygen dissolved in the tear film. Chronic deprivation leads to metabolic disturbances and structural damage. Excessive wear disrupts the tear film stability, increasing the risk of mechanical injury and microbial colonization. Rationale: A. Corneal abrasions occur when the contact lens becomes a mechanical irritant due to debris accumulation or protein deposits. Prolonged wear causes epithelial edema, making the corneal surface more fragile and prone to painful epithelial defects. These microscopic tears can serve as entry points for pathogens, potentially leading to microbial keratitis. B. Ocular hypoxia is a direct result of the physical barrier created by the lens, which restricts oxygen diffusion. This leads to anaerobic metabolism, resulting in lactic acid accumulation and stromal edema. Over time, the eye may develop neovascularization as it attempts to supply oxygen to the starved tissues via new blood vessel growth. C. Ocular allergies are generally immune-mediated hypersensitivity reactions to environmental allergens like pollen or dander. While contact lens solutions can cause contact dermatitis, "overwear" specifically refers to mechanical and hypoxic damage rather than an allergic immune response. Therefore, it is not a direct complication of the duration of lens wear itself. D. All of the above is incorrect because while abrasions and hypoxia are classic complications, ocular allergies are not traditionally caused by the duration of wear. Allergic responses require a specific allergen and an IgE-mediated pathway. Overwear primarily triggers ischemic and mechanical pathways of tissue injury rather than systemic allergic sensitization. E. A and B are the most accurate complications related to the physiological stress of keeping lenses in too long. The combination of mechanical friction leading to abrasions and the metabolic shift caused by hypoxia defines the clinical presentation of overwear. These factors collectively jeopardize the integrity of the ocular surface and require immediate lens cessation.