What is the benefit of using laboratory cleaners and solvents?

• A. Increases oxygen permeability
• B. Reduces cleaning time
• C. Decreases lens clarity
• D. Improves Wettability

Answer: (D)

Removing residues from the lens surface with laboratory cleaners and solvents improves wettability, which is how readily the tear film spreads over the lens. A clean surface has higher surface energy, so the tear film can spread more evenly across the lens, forming a stable, uniform layer. This leads to better comfort, smoother wear, and a clearer surface because the tear film interacts well with the lens. The oxygen permeability of the lens material is a property of the material itself and isn’t changed by cleaning, so cleaning mainly enhances how well the tear film wets the surface rather than altering the lens’s inherent oxygen transmission. If residues remain, wetting can be uneven, causing drying or discomfort, so proper cleaning to maintain a clean, well-wetted surface is key.