What is a key drawback of silicone lenses related to their surface characteristics?

Wettability is a crucial characteristic of silicone lenses that directly impacts their performance. Silicone materials typically have lower wettability compared to other lens materials, which means that they do not allow tears or other liquids to spread easily over their surfaces. This can lead to discomfort for the wearer, as insufficient wettability may result in dry spots on the lens, a decrease in visual clarity, and an overall less enjoyable wearing experience.

In contrast, while silicone lenses are known for their high oxygen permeability, allowing for more breathable eye wear, that characteristic does not represent a drawback but rather an advantage. Similarly, the ability to absorb moisture is typically limited in silicone lenses, making them less prone to fogging but not necessarily enhancing comfort. Lastly, flexibility under varying temperatures does not constitute a significant drawback as silicone lenses are designed to maintain their shape and performance across a range of temperatures. Therefore, the challenge of wettability stands out as a notable drawback regarding the surface characteristics of silicone lenses.