Which type of lens material allows more oxygen to reach the cornea?

Silicone hydrogel lenses are designed to allow significantly higher levels of oxygen to reach the cornea compared to other types of contact lens materials. This is primarily due to their unique composition, which integrates silicone, a material known for its excellent oxygen permeability. The high Dk (oxygen permeability) values associated with silicone hydrogel lenses facilitate a greater amount of oxygen diffusion, promoting corneal health and ensuring that the eyes can remain comfortable during extended wear.

In contrast, hydrogel lenses, while providing some oxygen transmission, generally have lower oxygen permeability compared to silicone hydrogels. Rigid gas permeable lenses also have good oxygen transmission but may not match the level provided by silicone hydrogels, especially in respect to continuous wear. PMMA (polymethyl methacrylate) lenses are essentially impermeable to oxygen, which can lead to corneal hypoxia if worn for extended periods. Thus, silicone hydrogel materials are often preferred for users needing enhanced oxygen supply to maintain corneal health and comfort.