The permeability of a contact lens is denoted by which value?

The permeability of a contact lens refers to its ability to allow oxygen to pass through the lens material, which is crucial for maintaining corneal health and comfort for the wearer. The correct value that denotes this permeability is DK.

In this context, 'D' represents the diffusion constant, while 'K' refers to the solubility of oxygen in the lens material. Higher DK values indicate greater oxygen permeability, which is particularly important for contact lenses that are worn for extended periods.

This property is essential for preventing complications such as hypoxia, where the corneal tissue does not receive enough oxygen, possibly leading to discomfort or more severe issues. Understanding DK values assists optometrists and contact lens fitters in selecting the best lenses suited for their patients' needs.