National Contact Lens Registry Advanced Certification (NCLE-AC) Practice Exam 2025 - Free NCLE-AC Practice Questions and Study Guide

High-Dk/t lenses are known for their higher oxygen permeability, which is crucial for ensuring that the cornea receives adequate oxygen while the lenses are worn. This increased oxygen permeability is critical for maintaining corneal health and reducing the risk of complications associated with hypoxia, such as corneal swelling and inflammation.

The "Dk" value refers to the material's oxygen permeability, while the "t" stands for thickness. A high-Dk/t lens allows more oxygen to pass through to the cornea compared to lower-Dk/t lenses, making them particularly beneficial for extended wear and for patients who may have increased metabolic demands on the cornea.

While options regarding dehydration risk and comfort during wear might seem relevant, they do not directly define what high-Dk/t lenses are primarily characterized by. Greater comfort can be influenced by many factors, including lens design and fit, and lower surface tension is related more to the wettability of the lens rather than its Dk parameter. Thus, the primary and defining feature of high-Dk/t lenses is their higher oxygen permeability, which underscores their importance in contact lens fitting and patient care.