Which type of lenses are gas permeable lenses?

Gas permeable lenses are characterized by their rigid and non-hydrophilic nature, which allows them to retain their shape while still facilitating oxygen transmission. The key feature of gas permeable lenses is that they are made from a material that permits oxygen to pass through, enhancing eye health by ensuring that the cornea receives adequate oxygen, similar to soft contact lenses but without the bulkiness.

While the option indicating hydrophobic materials and the requirement for a wetting agent may seem appealing, the hydrophobic nature typically refers to materials that resist moisture, which can lead to comfort issues for the wearer. In reality, gas permeable lenses are designed to be wetted upon application to prevent discomfort and provide clear vision.

Gas permeable lenses do not fall into the categories of hydrated or soft lenses, nor do they typically require a wetting agent in the same way that soft lenses do. They maintain their shape and are breathable, allowing for good ocular health. Understanding the material properties and breathability of gas permeable lenses is crucial for their proper use and care in contact lens fitting and maintenance.