Thicker edge profiles in GP lenses are most likely to influence which aspects?

• A. Higher power
• B. Comfort and lens position
• C. Diameter and hydration
• D. Comfort and lens position

Answer: (D)

Edge geometry in gas-permeable lenses largely governs how the lens interacts with the eyelids and tear film. A thicker edge changes the lid-edge contact during blinking and the way tears flow around the edge, which in turn shapes comfort and how stably the lens sits on the eye. When the edge provides a smoother, more predictable transition and a bit more edge stiffness, there’s typically less lid friction and irritation, improving comfort. At the same time, a sturdier edge can help the lens maintain a more centered, consistent position on the cornea, reducing unwanted movement between blinks. The optical power, overall diameter, and material hydration are set by other design aspects, so edge thickness mainly affects how comfortable the lens feels and how well it stays in place.