What are the FDA Groupings of contact lenses based on water content and ionic properties?

The FDA Groupings of contact lenses are categorized based on their water content and ionic properties, which are crucial in determining the lens's performance, biocompatibility, and suitability for different wearers.

The second grouping is classified as non-ionic and high water. Non-ionic lenses do not carry a charge, which helps reduce protein deposition on the lens surface, making them easier to care for and more comfortable for many wearers. High water content refers to the percentage of water within the lens material, which generally enhances oxygen permeability, promoting better eye health and comfort.

Understanding these classifications is essential for selecting the right type of contact lens for an individual's specific needs, taking into consideration factors like dryness, sensitivity, and overall eye health. The use of non-ionic materials with high water content has been found to be beneficial for many contact lens wearers, particularly those who experience discomfort with other types of lenses.