Contact Lens Micro-Protuberances for Tear Film Retention
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Solution Overview
Problem
Existing contact lenses, both soft and rigid gas permeable, suffer from issues such as dehydration leading to reduced comfort and increased infection risk, poor oxygenation, and high maintenance requirements, while aiming to combine the benefits of both types without their drawbacks.
Innovation Solution
A contact lens design featuring micro-protuberances and/or holes made from non-hydrophilic, biocompatible materials with a medium-low surface contact angle, allowing tear film retention and movement, reducing friction and infection risk, and maintaining comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soft contact lenses are made hydrophilic to improve comfort and oxygenation, then oxygen permeability and comfort are improved, but the lens absorbs tear film causing dehydration and increasing infection risk
Solution Approach 1:
The lens is segmented into hydrophilic zones (for oxygen permeability) and hydrophobic zones (for preventing infection), with the hydrophobic peripheral zone specifically designed to repel bacteria and viruses while the central hydrophilic zone maintains oxygen transmission to the cornea
Solution Approach 2:
Different regions of the lens have different wettability properties: the central optical zone is hydrophilic to allow oxygen permeability and comfort, while the peripheral zone is hydrophobic to prevent adhesion of bacteria and viruses, creating localized functional zones that address both oxygenation and infection prevention needs
2Reliability
If soft contact lenses absorb tear film to improve oxygenation, then oxygen permeability is improved, but lens dehydration occurs reducing comfort
Solution Approach 1:
The lens structure divides the tear film interaction into functional zones: the central hydrophilic zone selectively absorbs minimal tear film for oxygen permeability while the hydrophobic peripheral zone prevents excessive tear film absorption, maintaining adequate lens hydration and comfort
Solution Approach 2:
The contact angle parameter is modified across different lens zones, with the peripheral hydrophobic zone having a higher contact angle (greater than 90 degrees) to reduce wettability and prevent excessive tear film absorption, thereby maintaining lens hydration and comfort while allowing oxygen permeability in the central zone
3Object-affected harmful factors
If RGP lenses are made hydrophobic to prevent infection, then infection risk is reduced, but comfort and tolerability decrease
Solution Approach 1:
The lens is divided into functional zones where the central hydrophilic zone provides comfort through tear film absorption and lens softness, while the peripheral hydrophobic zone prevents infection by repelling bacteria and viruses, combining benefits of both hydrophilic and hydrophobic materials in a single lens structure
Solution Approach 2:
The contact lens is constructed as a composite structure with hydrophilic and hydrophobic regions, where the hydrophilic central zone provides comfort and oxygen permeability while the hydrophobic peripheral zone provides infection resistance, effectively combining properties of different material types in one integrated lens
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 lens provides enhanced comfort, reduces infection risk, and simplifies maintenance while maintaining natural corneal hydration and oxygenation, with production costs comparable to existing lenses.
Implementation Method 1
A contact lens made from a non-hydrophilized, biocompatible material... which has not been subjected to any hydrophilization treatment... prevents the 'sponge effect' typical of soft contact lenses
Implementation Method 2
contact lens comprises an internal zone which extends within a visual diameter Dv... and a peripheral zone which is completely outside the visual diameter Dv... micro-protuberances disposed on the internal surface of the peripheral zone
Implementation Method 3
The contact lens has a medium-low surface contact angle, comprised between 10° and 60°... reduce the friction between the lens and the eyelids to a minimum
Data Source
Figure 1~1a
Figure 2a~3d
Figure 4~5
AI summary
Contact lens (10) that, during use, creates a hollow space between its concave internal surface and the convex external surface of the eye and contacts the corneal epithelium only for a fraction of its internal surface facing toward the eye thanks to the presence of a plurality of micro-protuberances (13) which allow to raise the contact lens (10) by a few micrometers with respect to the corneal surface.