Additive Manufacturing Contact Lens for Color Vision Deficiency
Solution Overview
Problem
Color vision deficiency (CVD) affects individuals' ability to distinguish between colors, leading to visual impairments that restrict certain professions and daily activities, as existing solutions do not effectively address the underlying cone cell sensitivity issues.
Innovation Solution
A contact lens with a tinted region made from 2-hydroxyethyl methacrylate (HEMA) and polyethylene glycol dimethacrylate (PEGDA) containing dyes that block specific wavelengths of light, manufactured using additive manufacturing, to correct color perception by altering the activation levels of cone cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional contact lenses without specialized optical properties are used, then manufacturing simplicity is maintained, but color identification accuracy remains poor for individuals with CVD
Solution Approach 1:
The contact lens is divided into multiple regions with different optical properties. The lens includes a first region with a first dye concentration and a second region with a second dye concentration, allowing different parts of the lens to perform different functions in correcting color vision deficiency. This segmentation enables targeted correction for different wavelength ranges while maintaining overall lens functionality.
Solution Approach 2:
Different regions of the contact lens are assigned different dye concentrations to create localized optical properties. The first region has a higher concentration of a first dye to block specific wavelengths, while the second region has a different dye concentration to address other wavelength ranges. This local quality approach allows the lens to provide customized correction for different parts of the visual spectrum.
2Measurement precision
If dye is added to the contact lens material, then color perception correction is improved, but material safety and biocompatibility become concerns
Solution Approach 1:
The patent carefully controls the concentration parameters of dyes within the contact lens material. By optimizing the dye concentration to be within 0.001% to 1% by weight, the lens achieves effective color correction while maintaining safety and biocompatibility. This parameter optimization ensures that the dye levels are sufficient for optical correction but low enough to avoid ocular toxicity.
Solution Approach 2:
The contact lens uses a composite material system combining hydrophilic polymer matrix (such as HEMA) with carefully selected dye molecules. This composite structure allows the dyes to be effectively distributed and fixed within the lens material, providing stable optical correction while the polymer matrix ensures biocompatibility and safety for ocular use.
3Manufacturing precision
If additive manufacturing is used to manufacture the contact lens, then manufacturing precision and customization are improved, but manufacturing process complexity increases
Solution Approach 1:
The contact lens design incorporates support structures that are formed along with the lens during additive manufacturing. These support structures are prepared in advance as part of the printing process and are subsequently removed after manufacturing. This preliminary action approach simplifies the overall manufacturing process by integrating support structure creation into the main printing operation, even though the final product requires removal of these temporary structures.
Solution Approach 2:
The patent replaces traditional mechanical contact lens manufacturing methods (such as molding or cutting) with additive manufacturing technology. This substitution enables precise control over lens geometry, dye distribution, and regional variations that would be difficult or impossible to achieve with conventional mechanical processes, although it requires specialized 3D printing equipment and processes.
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 contact lens provides significant improvements in color identification for individuals with deuteranomaly and protanomaly, with customized dye concentrations offering up to 25% improvement in correctly identifying colors in the Ishihara test, while being non-toxic and stable for use in the eye.
Implementation Method 1
forming a support structure on a planar print bed of the additive manufacturing apparatus by depositing a first plurality of layers of the first solution and curing the first plurality of layers
Implementation Method 2
containing dyes that block specific wavelengths of light
Data Source
AI summary
A method of forming an ophthalmic contact lens using an additive manufacturing apparatus is presented herein. The method providing a first solution comprising HEMA, PEGDA, and a photoinitiator, forming a support structure on a planar print bed of the additive manufacturing apparatus by depositing a first plurality of layers of the first solution and curing the first plurality of layers, and forming an ophthalmic contact lens on the support structure by depositing a second plurality of layers of the first solution and curing the second plurality of layers. The second plurality of layers are arranged such that a disc of the ophthalmic contact lens is oriented generally perpendicular to the planar print bed of the additive manufacturing apparatus.