What type of GP lenses are more prone to warpage?

• A. High Dk
• B. Hyper Dk
• C. Low Dk
• D. Standard Dk

Answer: (B)

Warpage in gas-permeable lenses is driven by how the lens material behaves under wear and care stresses. Materials with higher oxygen permeability (high Dk) tend to be more flexible and often have higher water content. That combination makes the lens more prone to swelling and deformation when it's worn, handled, or subjected to disinfection cycles. The extra flexibility means the lens can permanently change shape‑wise more readily than stiffer, lower‑Dk materials, so high Dk GP lenses are more susceptible to warpage. In contrast, lower Dk or standard Dk materials are typically stiffer and less prone to this kind of permanent deformation.