Hydrogel Ocular Lens UV Absorber Compatibility
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Solution Overview
Problem
Current UV-absorbing hydrogel ocular lenses face challenges in achieving effective UV blocking while maintaining acceptable water content and optical transparency, as many UV absorbers are hydrophobic, compromising compatibility with hydrogel-forming monomers and leading to issues like leaching and undesirable tints.
Innovation Solution
The development of hydrogel ocular lenses incorporating a polymerisable UV absorber with a hydrophilic non-polyalkylene glycol linker, which covalently bonds with the base polymer, enhancing compatibility and retention of UV-absorbing properties without compromising hydrogel characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If hydrophobic UV absorbers are incorporated into hydrogel ocular lenses, then UV blocking capability is improved, but compatibility with hydrogel-forming monomers deteriorates and leaching occurs
Solution Approach 1:
The patent modifies the chemical parameters of UV absorbers by introducing hydrophilic groups (carboxyl, hydroxyl, amine) to create water-soluble derivatives. This parameter change enables the UV absorbers to be compatible with hydrogel-forming monomers while maintaining their UV blocking capability, preventing leaching issues associated with hydrophobic UV absorbers.
Solution Approach 2:
The patent creates composite UV absorber molecules that combine hydrophobic UV-absorbing moieties with hydrophilic groups. This composite structure allows the UV absorber to maintain its UV blocking function while gaining compatibility with hydrogel matrices, effectively resolving the contradiction between UV protection and material compatibility.
2Object-affected harmful factors
If higher concentrations of UV absorbers are used to improve UV blocking, then UV protection is enhanced, but undesirable tints and reduced optical transparency occur
Solution Approach 1:
The patent changes the molecular parameters of UV absorbers by adding hydrophilic groups, which alters their solubility and interaction with the hydrogel matrix. This enables effective UV blocking at lower concentrations, preventing the formation of undesirable tints and maintaining optical transparency while still achieving ISO Class II or Class I UV protection standards.
3Object-affected harmful factors
If UV absorbers are blended with base polymer, then UV protection is provided, but the absorbers leach out during use
Solution Approach 1:
The patent merges the UV absorber molecules with the hydrogel matrix through covalent bonding by incorporating polymerizable groups into the UV absorber structure. This merging ensures the UV absorbers remain permanently embedded in the lens material, preventing leaching while maintaining UV protection throughout the lens lifecycle.
Solution Approach 2:
The patent develops composite UV absorber structures that include both UV-absorbing moieties and polymerizable groups. These composite molecules can be covalently integrated into the hydrogel network, creating a stable composite material that provides durable UV protection without leaching.
4Use of energy by moving object
If silicone components are incorporated to improve oxygen permeability, then oxygenation to cornea is enhanced, but hydrophobicity increases causing discomfort and deposits
Solution Approach 1:
The patent modifies the surface parameters of silicone hydrogel lenses by incorporating hydrophilic UV absorbers with charged groups (carboxyl, hydroxyl, amine). These parameter changes increase surface hydrophilicity, reducing water contact angle and preventing protein deposits, while maintaining the high oxygen permeability provided by silicone components.
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 effectively blocks UV radiation while maintaining high water content and optical transparency, preventing leaching and minimizing tint issues, thus meeting ISO Class II or Class I UV blocking standards without adverse effects on the lens's physical properties.
Implementation Method 1
a polymerisable UV absorber of formula (I)... which covalently bonds with the base polymer
Implementation Method 2
U is a UV absorbing moiety... capable of blocking UV radiation
Data Source
AI summary
Ocular lenses having UV absorbing properties are disclosed. The ocular lens comprises a hydrogel polymer comprising polymerised residues derived from a polymerisable UV absorber of formula (I):U-L-Py (I)wherein: U is a UV absorbing moiety; L is a hydrophilic non-polyalkylene glycol linker comprising an anionic, a zwitterionic or a saccharide moiety; and Py is an ethylenically unsaturated polymerisable moiety.