Micro- and Nano-Scale Patterns Improve Functionality of Hydrogel Contact Lenses
The surface gel layer of these silicone hydrogel contact lenses are patterned with micro- and nano-scale wells, protrusions, and channels to better lubricate the lenses and make wearing them more comfortable. More than 30 million people in the United States alone wear contact lenses. The most commonly expressed reason for discontinuing wearing contacts is discomfort caused by dryness or irritation. Silicone hydrogel contact lenses have reduced wearer discomfort by improving oxygen transmissibility. Some lenses improve on the silicone hydrogel design by adding a high-water-content surface layer, making the lenses even more comfortable. University of Florida researchers have discovered that adding micro- and nano-scale surface textures and patterns in that high-water-content, surface hydrogel layer further increases fluid transport and wetting, reducing friction-based discomfort even more.
Optimal surface topography in high-water-content layer of silicone hydrogel contact lenses increases lubricity and comfort
- Topographical patterns in the surface gel layer target three problem areas in available silicone-based contact lenses, improving lubricity and comfort
- Reduces pressure on nerve beds of the cornea as well as nerves on the underside of eyelid, increasing comfort while minimizing damage to lenses
- Increases fluid transport and wetting, allowing contacts to function better and ensure comfort for users
These contact lenses are molded with micro- and nano-scale textures and patterns for hydrogel contact lens surfaces that allow for controlled wetting and improved lubricity for wearers. Available state-of-the-art contact lenses have smooth surfaces with an added layer of high-water-content hydrogel, over which an eyelid traverses with relatively high friction. University of Florida researchers have molded hydrogel lenses to mitigate the pressure distribution and friction by topographies that decrease contact and control the manner of fluid flow across the lens that occurs during blinking. For improved lubricity, these four patterns target a different area of the contact lens: the periphery of outer lens, periphery of inner lens, central region on underside of lens, and central region on outer-side of lens. Patterns would include micro-scale wells to support pressure at eyelid contact, micro-scale channels acting as fluid pumps to direct tear transport, and a combination of nano-wells and nano-protuberances and nano-scale roughness that would enhance lubricity during blinking. Optimal surface topography of the hydrogel lens results in increased lubricity and comfort and could be used for specialized contact lenses for healthy eyes as well as for patients with lacrimal gland or lipid deficiencies.