Silicone Hydrogel Lenses: The Future of Contact Lenses
The Evolution of Silicone Hydrogel Lenses
Silicone hydrogel lenses were first conceptualized over two decades ago. The potential benefits were clear, but the technological challenge was akin to combining oil and water. Researchers have invested significant time and resources to develop the advanced soft lenses we use today, believing that silicone hydrogel is the future standard for contact lenses.
Oxygen Transport: A Key Benefit
What makes silicone hydrogel so special as a lens material? Its primary benefit is its ability to transmit oxygen to the eye, maintaining proper eye health. Modern contact lens technology focuses on improving oxygen permeability, measured using the "Dk" index. For optimal eye health, a higher Dk value is essential.
In traditional hydrogel contact lenses, the Dk is linked to the amount of water the lens can hold, as oxygen dissolves in the water and diffuses through the lens. However, in silicone hydrogel lenses, the Dk increases with silicone content rather than water content, allowing for far greater oxygen transmission compared to older lens materials.
Overnight Wear and Silicone Hydrogel Lenses
According to market research, 84% of contact lens wearers occasionally sleep with their lenses in, and 33% admit to doing so regularly. Among those who wear one-to-two-week disposable lenses, 25% often sleep with their lenses overnight, even though their oxygen permeability is low.
With silicone hydrogel lenses, interest is high because they allow for safer overnight wear. About 72% of lens wearers expressed a desire to be able to sleep in their lenses if it were safe.
Handling and Comfort of Silicone Hydrogel Lenses
Silicone hydrogel lenses are generally more rigid than traditional hydrogel lenses due to the silicone content. This rigidity makes the lenses easier to handle, making them ideal for users with less delicate touch. However, this stiffness can reduce the ability of the lenses to mold perfectly to the eye's shape, potentially leading to decreased comfort for some wearers.
Reduced Deposits for Cleaner Lenses
Protein and lipid deposits can build up on contact lenses over time, affecting lens clarity and eye health. The amount of buildup depends on the duration of wear, the lens material, and the tear composition of each individual wearer. Regular replacement of traditional lenses helps mitigate this problem, but silicone hydrogel lenses are more resistant to deposits due to their unique material composition.
No comments:
Post a Comment