Which feature is not a direct result of plasma treatment on GP lenses?

Which feature is not a direct result of plasma treatment on GP lenses?

• A. increased wettability
• B. improved comfort
• C. lower oxygen permeability
• D. removal of contaminants

Answer: (C)

Plasma treatment on GP lenses mainly changes the surface properties of the lens. By increasing the surface energy, the lens becomes more hydrophilic, so tears spread more easily across the surface. That directly improves wettability, which helps the tear film hold onto the lens and enhances comfort. The treatment also has a cleaning effect on the surface, helping to remove or reduce contaminants that can accumulate during handling and wear. Oxygen permeability, however, is a bulk property determined by the lens material and its thickness. Plasma treatment alters only the outermost surface and does not intend to change the material’s inherent oxygen transmission. So, this surface modification does not directly lower (or otherwise meaningfully alter) the oxygen permeability.

Plasma treatment on GP lenses mainly changes the surface properties of the lens. By increasing the surface energy, the lens becomes more hydrophilic, so tears spread more easily across the surface. That directly improves wettability, which helps the tear film hold onto the lens and enhances comfort. The treatment also has a cleaning effect on the surface, helping to remove or reduce contaminants that can accumulate during handling and wear.

Oxygen permeability, however, is a bulk property determined by the lens material and its thickness. Plasma treatment alters only the outermost surface and does not intend to change the material’s inherent oxygen transmission. So, this surface modification does not directly lower (or otherwise meaningfully alter) the oxygen permeability.