Clinical Info » The Silicone Hydrogel Material » UltraVision’s Silicone Hydrogel
Definitive™ SiH material has a unique combination of properties that make it ideal for all types of contact lens wearer.
The high water content of 74% enables the lens to provide a moist environment for the eye.
Due to the specific chemical properties of the material, it retains water throughout the day, losing less that 2% of water in a whole day’s normal wear. This enables the contact lens to retain its oxygen permeability (DK/t) at a stable level throughout the day, whilst also providing the user with consistent comfort and optical clarity throughout the day.
The fit of the lens remains the same throughout the day as there is no shrinkage or warping due to the excellent water retention of the material.
The Definitive™ material has the water retention properties built into the unique chemistry of the material, and therefore no surface treatment is required. This results in 3 major benefits:
The modulus (stiffness) of the material is very low. This enables the contact lenses to be a soft as a normal soft lens material, be flexible in the eye and hence be more comfortable for longer wearing times.
The combination of high water retention, low modulus and surface wettability makes these lenses exceptionally comfortable. Patients who have worn these lenses in dry conditions, for example in air conditioned offices, have commented on their daylong comfort. They report higher levels of comfort than with most other lenses they have worn.
Definitive™ is a trademark of Contamac Ltd.