Contact Lens Color Indicator for Wear-Time Replacement

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Solution Overview

Problem

Contact lenses do not include a simple indicator to signal a wearer that a lens needs to be replaced beyond its recommended wearing schedule, leading to potential discomfort and increased risk of infection.

Innovation Solution

Incorporating an indicator system into contact lenses that visually changes color based on a concentration change of a trigger, indicating the elapsed time since removal from packaging or use, using nanoparticles stabilized by capping agents or chromophores, which aggregate to show discrete color changes at predetermined times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If contact lenses are worn beyond the recommended replacement schedule, then the lens can continue to provide vision correction, but the risk of infection and discomfort increases due to accumulated deposits

Engineering Contradiction:
Improvelens wear timeVSAvoidinfection risk and discomfort
Core Design Contradiction:
Duration of action of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent incorporates a color-changing indicator system into the contact lens that visually signals when the lens has been worn for the recommended duration. The indicator changes color in response to chemical changes in the tear film that occur over time, providing a clear visual cue to the wearer that the lens needs replacement, thereby preventing infection and discomfort associated with extended wear.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent implements a feedback mechanism where the indicator continuously monitors the wear condition of the lens and provides real-time visual information to the wearer. The indicator system responds to chemical changes in the ocular environment that correlate with wear time and lens condition, giving the wearer feedback about when to replace the lens to maintain eye health.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If a simple visual indicator system is added to contact lenses, then wearers can easily track lens replacement timing, but the device complexity increases

Engineering Contradiction:
Improvelens replacement trackingVSAvoidindicator system structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent employs a self-service indicator system that automatically changes color in response to chemical changes in the tear film without requiring any action from the wearer. The indicator utilizes chemical reactions between components embedded in the lens and substances in the tear film that naturally occur over time, eliminating the need for manual tracking or external power sources.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces complex mechanical or electronic tracking systems with a simple chemical-based color-changing indicator. Instead of using batteries, circuits, or mechanical components to track wear time, the system utilizes chemical reactions that occur naturally in the ocular environment, significantly reducing device complexity while maintaining ease of use.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If an indicator system using nanoparticles and chromophores is incorporated into contact lenses, then clear visual signals can be provided, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecolor change detectionVSAvoidindicator component integration
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent merges the indicator components (nanoparticles, capping agents, and chromophores) directly into the contact lens matrix during the manufacturing process. By combining multiple functional components into a single integrated system within the lens material, the patent achieves precise color change detection while managing manufacturing complexity through a unified fabrication approach.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent utilizes composite materials consisting of nanoparticles stabilized by capping agents combined with chromophores embedded in the contact lens matrix. This composite structure enables precise color change detection through coordinated interactions between the different components, while the integrated manufacturing process ensures consistent distribution and positioning of all indicator elements.

Inventive Principle:
Principle #40Composite materials

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

Provides a clear visual signal for timely lens replacement, reducing discomfort and infection risk by ensuring adherence to wear schedules.

Implementation Method 1

using nanoparticles stabilized by capping agents or chromophores, which aggregate to show discrete color changes at predetermined times

Methodology Applied
Scientific EffectAggregation: Coagulation

Data Source

PatentEP4165465B1Systems and methods for indicating the time elapsed since the occurrence of a triggering event
Publication Date: 2026.02.18 JOHNSON & JOHNSON VISION CARE INC
  • EP4165465B1 patent drawingFigure 1A~1B
  • EP4165465B1 patent drawingFigure 1C
  • EP4165465B1 patent drawingFigure 1D

AI summary

Described are systems and methods which can be used to indicate the period of time elapsed since the occurrence of a triggering event. More particularly, this application relates to systems and methods which can be used to visually indicate the time period elapsed since an article has been removed from its packaging. The system can include an indicator disposed on or within the article and a trigger disposed within the receptacle and in contact with the indicator. The article may be enclosed within a sealable receptacle of the package. The indicator is responsive to a change in a concentration of the trigger in contact with the indicator. The removal of the article from the receptacle can induce a change in concentration of the trigger in contact with the indicator. The change in the concentration of the trigger can induce a change in color in the indicator. The color change indicates a predetermined period of time has elapsed since the article has been removed from the receptacle. The predetermined period of time is from 30 minutes to 30 days, such as from 1 hour to 30 days.