Which lens type is specifically designed to be worn over an existing contact lens?

The lens type that is specifically designed to be worn over an existing contact lens is known as the piggyback lens system. This method involves placing a soft contact lens over a rigid gas permeable lens. The primary purpose of this combination is to enhance comfort while providing the optical benefits of a rigid lens. The soft lens acts as a cushion, reducing any discomfort that the wearer might experience from the rigid lens, while still benefiting from the vision correction provided by both lens types.

Piggyback systems are particularly beneficial for individuals who require the clarity and stability of rigid lenses but find them too uncomfortable to wear alone. This solution allows wearers to achieve better vision without compromising on comfort, making it a popular choice in specific patient scenarios.