Which feature is listed as a characteristic of high-Dk hard lens materials?

Which feature is listed as a characteristic of high-Dk hard lens materials?

• A. Better surface wettability
• B. Lower oxygen permeability
• C. Increased scratch resistance
• D. More oxygen permeability

Answer: (D)

Oxygen transmission through the lens is what high-Dk materials are all about. Dk represents how readily oxygen can pass through the lens material, and a higher Dk means more oxygen reaches the cornea for a given lens thickness. This is crucial for corneal health during wear, especially with thicker or longer-wear lenses, because adequate oxygen helps keep the cornea from swelling and maintains metabolism. So, the defining feature of high-Dk hard lens materials is more oxygen permeability. Other properties like how well tears spread on the surface or how resistant the surface is to scratching relate to comfort and durability, not to how much oxygen passes through the lens.

Oxygen transmission through the lens is what high-Dk materials are all about. Dk represents how readily oxygen can pass through the lens material, and a higher Dk means more oxygen reaches the cornea for a given lens thickness. This is crucial for corneal health during wear, especially with thicker or longer-wear lenses, because adequate oxygen helps keep the cornea from swelling and maintains metabolism. So, the defining feature of high-Dk hard lens materials is more oxygen permeability. Other properties like how well tears spread on the surface or how resistant the surface is to scratching relate to comfort and durability, not to how much oxygen passes through the lens.