What common issue can occur if a contact lens is worn beyond its recommended replacement schedule?

Wearing a contact lens beyond its recommended replacement schedule can significantly increase the risk of infection. This is primarily due to the accumulation of deposits, such as protein, lipids, and various debris on the lens surface, which can create an environment conducive to bacterial growth. As the lens ages, it may also lose its moisture retention capabilities, leading to discomfort and potentially exacerbating any irritation or damage to the cornea.

Moreover, older lenses can become less effective in their optical performance, which can contribute to problems with vision clarity. The risk of hypoxia (oxygen deprivation to the cornea) also increases because older lenses may not allow adequate oxygen transmission. All of these factors combined heighten the likelihood of developing complications, including keratitis or other serious eye infections.

It's crucial for wearers to adhere to prescribed replacement schedules to maintain eye health and comfort while using contact lenses.