High Refractive Index Siloxane Inserts for Contact Lenses
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing contact lens inserts have low oxygen permeability and refractive index, which can negatively impact corneal health and optical performance, respectively.
Innovation Solution
A crosslinked polymeric material comprising vinyl-functional polysiloxane, aryl acrylic monomer, and vinylic crosslinking agent, with a composition that ensures high oxygen permeability and refractive index, is used to create inserts for embedded silicone hydrogel contact lenses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional non-hydrogel materials are used for inserts, then manufacturing and handling is easier, but oxygen permeability is low which negatively impacts corneal health
Solution Approach 1:
The patent uses a composite polymeric material comprising polysiloxane units with vinyl groups, aryl acrylic monomers, and crosslinking agents to create an insert that achieves both high oxygen permeability (≥40 barrers) and improved mechanical properties. This composite structure allows the material to function as a gas permeable barrier while maintaining structural integrity for manufacturing and handling.
Solution Approach 2:
The patent modifies the chemical composition parameters of the insert material by incorporating specific ratios of polysiloxane units (at least 15% by mole with phenyl substituents), aryl acrylic monomers, and crosslinking agents. These parameter changes enable the material to achieve a glass transition temperature >30°C and water content <5%, resulting in high oxygen permeability while improving handling characteristics.
2Reliability
If conventional materials with low refractive index are used, then manufacturing is simpler, but optical performance is reduced
Solution Approach 1:
The patent employs a composite polymeric system combining polysiloxane backbone structures with aryl acrylic side groups to achieve a refractive index of at least 1.47. The phenyl substituents on the siloxane units contribute to the high refractive index while the overall crosslinked structure maintains manufacturability through standard polymerization processes.
Solution Approach 2:
The patent changes the chemical composition parameters by incorporating aryl acrylic monomers and phenyl-substituted siloxane units in specific proportions (at least 70% by weight of components 1 and 2 combined). These parameter adjustments achieve the target refractive index of ≥1.47 while maintaining the material's processability and structural integrity for embedded contact lens manufacturing.
3Reliability
If high oxygen permeability and high refractive index materials are used, then corneal health and optical performance improve, but the material becomes soft and sticky making handling difficult
Solution Approach 1:
The patent adjusts key parameters including glass transition temperature (>30°C), water content (<5%), and chemical composition ratios to achieve the desired balance. The crosslinking density and molecular weight distribution are controlled to ensure the material remains sufficiently rigid for handling while maintaining high oxygen permeability (≥40 barrers) and refractive index (≥1.47).
Solution Approach 2:
The patent creates a crosslinked composite polymer network combining polysiloxane units, aryl acrylic monomers, and crosslinking agents. This composite structure provides both the high oxygen permeability and refractive index needed for corneal health and optical performance, while the crosslinked network maintains mechanical stability for ease of handling and manufacturing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution provides inserts with enhanced oxygen permeability and refractive index, improving corneal health and optical performance while addressing manufacturing and handling challenges associated with softness and stickiness.
Implementation Method 1
an oxygen permeability of at least about 40 barrers
Implementation Method 2
a refractive index of at least about 1.47
Data Source
AI summary
The invention is generally related to an insert for being embedded in a silicone hydrogel contact lens. The insert is made of a crosslinked materials which are rigid in dry state at room temperature (from about 22ºC to about 26ºC), have a high oxygen permeability and a high refractive index in fully hydrated state. Such materials are useful for making inserts in embedded contact lenses for correcting corneal astigmatism, presbyopia, and color blindness lenses and for imparting photochromic characteristics to the lenses. The invention is also related to a method for making embedded silicone hydrogel contact lenses comprising an insert of the invention therein and to embedded silicone hydrogel contact lenses comprising an insert of the invention therein.