Which PMMA property is listed among its advantages?

Which PMMA property is listed among its advantages?

• A. Wettability
• B. Brittleness
• C. Non-wetting
• D. Poor durability

Answer: (A)

Wettability is about how readily tear film spreads across the lens surface. A lens material that wets well allows the tear film to form a continuous, smooth layer, which reduces surface friction, enhances comfort, and helps keep the surface clean and stable during wear. PMMA can be finished or treated to improve this wetting behavior, making wettability a beneficial property for rigid lenses. In contrast, brittleness, non-wetting, and poor durability describe drawbacks: brittleness risks cracking, non-wetting leads to dry spots, and poor durability means the lens wears out faster. So, among these options, the positive property is good wettability.

Wettability is about how readily tear film spreads across the lens surface. A lens material that wets well allows the tear film to form a continuous, smooth layer, which reduces surface friction, enhances comfort, and helps keep the surface clean and stable during wear. PMMA can be finished or treated to improve this wetting behavior, making wettability a beneficial property for rigid lenses. In contrast, brittleness, non-wetting, and poor durability describe drawbacks: brittleness risks cracking, non-wetting leads to dry spots, and poor durability means the lens wears out faster. So, among these options, the positive property is good wettability.