Contact Lens Cholesteric Liquid Crystal Compliance Indicator
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Solution Overview
Problem
There is a lack of visible indicators on contact lenses to signal when they have been used beyond their recommended replacement time, posing safety and health risks as users often forget or are unaware of the wear schedule.
Innovation Solution
Incorporating a compliance indicator made from cholesteric liquid crystal materials that change from an invisible to a visible state over time when exposed to visible light, indicating the end of the recommended wear period, which can be designed as a colored patch or marking on the lens.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact lenses are made from transparent materials to ensure optical clarity, then vision quality is improved, but users cannot visually track wear time and may exceed replacement schedules
Solution Approach 1:
The contact lens incorporates a cholesteric liquid crystal layer that changes from transparent to colored (red) when exposed to visible light for extended periods. This color change provides visual feedback to users about lens wear time without compromising the optical clarity of the lens during its service life.
Solution Approach 2:
The optical parameters of the contact lens change based on cumulative light exposure. The cholesteric liquid crystal layer's optical properties evolve from transparent to reflective as the lens accumulates wear time, providing an objective indicator of when replacement is needed.
2Ease of operation
If contact lenses are designed with visible indicators to show wear time, then user compliance is improved, but the lens structure becomes more complex
Solution Approach 1:
The compliance indicator is merged with the contact lens structure itself rather than being a separate component. The cholesteric liquid crystal layer is integrated into the lens, allowing it to serve both as a structural element and a wear-time indicator simultaneously.
Solution Approach 2:
A simple color change mechanism is used instead of complex electronic displays or multiple indicators. The cholesteric liquid crystal layer provides a clear visual signal through color transition, making the compliance indicator easy to understand and interpret without adding significant structural complexity.
3Ease of operation
If contact lenses use materials with high oxygen permeability to ensure comfort, then wearability is improved, but the materials do not provide inherent wear time indication
Solution Approach 1:
The oxygen permeability function and the wear-time indication function are combined in a single integrated lens structure. The cholesteric liquid crystal layer is incorporated into the contact lens material, allowing the lens to simultaneously provide comfort through high oxygen permeability and visual feedback through color change.
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
This solution provides a simple and inexpensive way for users to adhere to recommended wear times, ensuring safety, health, and comfort by visibly signaling when contact lenses need to be replaced.
Implementation Method 1
a compliance indicator made from cholesteric liquid crystal materials that change from an invisible to a visible state over time when exposed to visible light
Implementation Method 2
a material that when exposed to visible light causes the material to change from transparent to visible over a predetermined period of time
Data Source
AI summary
An ophthalmic lens incorporating a usage compliance indicator may be utilized to indicate when the lens should be discarded or otherwise treated. The usage compliance indicator comprises a material that is clear when the lens is removed from its packaging and transforms to a visible marking over a given period of time corresponding to the manufacturer's suggested usable time. The material is compatible with the lens material and does not interfere with the optics.