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Contact lenses are widely used for vision correction and cosmetic purposes. Smart contact lenses offer further opportunities as functionalized non-invasive devices capable of simultaneous vision correction, real-time health monitoring and patient specific drug delivery. Herein, a low-cost vat photopolymerization technique is developed for directly 3D printing functionalized structures on commercially available contact lenses. The process enables controlled deposition of functionalized hydrogels, in customizable patterns, on the commercial contact lens surface with negligible optical losses. Multi-functional contact lenses can also be 3D printed with multiple materials deposited at different regions of the contact lens. Herein, the functionalities of colour blindness correction and real-time UV monitoring are demonstrated, by employing three suitable dyes incorporated into 2-hydroxyethyl methacrylate (HEMA) hydrogel structures printed on contact lenses. The results suggest that 3D printing can pave the way towards simple production of low-cost patient specific smart contact lenses. [ABSTRACT FROM AUTHOR]

This work investigates the influence of MXene content on the mechanical and functional response of PLA‐MXene composites fabricated additively using fused deposition modeling. The mechanical, thermal, and microstructural properties of the fabricated samples are investigated considering dense and architected triply periodic minimal surfaces (TPMS) gyroid specimens. Overall, the addition of 0.25–0.5 wt% MXene is found to improve the stiffness, fracture strength, and energy absorption capabilities of the PLA. However, further increasing MXene content to 1 wt% becomes detrimental to the general performance of the composite. In terms of functional behavior, the PLA‐MXene blends developed in this work are shown to display a shape memory effect, wherein deformed samples are shown to recover their shape when submerged in hot water. The reported results provide insights into the use of PLA‐MXene in engineering applications, namely those involving impact shielding or energy absorption. [ABSTRACT FROM AUTHOR]

Ocular diseases can cause vision problems or even blindness if they are not detected early. Some ocular diseases generate irregular physical changes in the eye; therefore, reliable diagnostic technology for continuous monitoring of the eye is an unmet clinical need. In this study, a pulsed laser (Nd:YAG) was used to create optical nanostructures on a hydrogel-based commercial contact lens. Simulations were used to determine the spacing of the nanostructures, which were then produced and tested on the lens in ambient humidity and fully hydrated environments. The nanostructures produced a 4° diffraction angle difference in response to the environmental changes. Vision obstruction was considered while designing the nanostructure features on the lens. The curved nanostructures exhibited a series of visible rainbow colors with an average range of 8° under normal room light. A spherical surface was also used to simulate the human eye, and application of a force (curvature change) caused the nanostructure spacing to change, influencing the visible color of the contact lenses. A smartphone camera application was used to measure the progress of ocular diseases by analyzing the RGB color values of the visible color. The nanostructures were also responsive to K+ ion variations in artificial tear fluids, with a 12 mmol L−1 sensitivity, which may allow the detection of ocular ionic strength changes. A pulsed laser created optical nanostructures (holograms) on hydrogel-based soft contact lenses. The nanostructures produced varying diffraction patterns in response to the environmental changes. Vision obstruction was considered while designing the nanostructure features on the lens surface. A change in curvature of the contact lens caused the nanostructure spacing to change, influencing the visible color of the hologram. A smartphone camera application was used to monitor the diffraction colors by analyzing the RGB color values. [ABSTRACT FROM AUTHOR]

Hydrogel optical fibers are utilized for continuous glucose sensing in real time. The hydrogel fibers consist of poly(acrylamide-co-poly(ethylene glycol) diacrylate) cores functionalized with phenylboronic acid. The complexation of the phenylboronic acid and cis-diol groups of glucose enables reversible changes of the hydrogel fiber diameter. The analyses of light propagation loss allow for quantitative glucose measurements within the physiological range.

Biogenic gold nanoparticles (BAu NPs) synthesized using olive leaf extract were used as an additive in commercial contact lenses (BAu lens). Their antibacterial and color blindness‐correcting properties were examined. To compare the properties, gold nanocomposite contact lenses were also synthesized using the well‐known Turkevich method (TAu lens). The breath‐ in/breath‐out method was used to load the Au NPs onto commercial contact lenses. The bio‐gold nanoparticles showed good dispersion and stability within the lens hydrogel matrix. Nanoparticle loading had a negligible effect on the contact lenses' wettability and swelling properties. BAu lens filtered around 55% of visible light at 530 nm, a problematic wavelength for color blind patients. The optical filtering results were comparable with Pilestone commercial color blind correction glasses. BAu lenses also showed superior resistance against the attack of Pseudomonas aeruginosa and Staphylococcus aureus bacteria as compared to Tau lenses. As scanning electron microscopy (SEM) imaging showed, the BAu lenses showed a complete lack of surface attachment toward the bacterial colonies. This research provides a cost‐effective and scalable method of producing multi‐functional nanocomposite contact lenses with antibacterial and color blind correction properties. [ABSTRACT FROM AUTHOR]

Diabetes mellitus (DM) presents a substantial global health concern due to elevated blood glucose levels, necessitating an affordable, rapid, and reliable continuous glucose monitoring (CGM) solution. In this pursuit, a pioneering approach is introduced utilizing optical fiber (OF) sensors based on nanocomposite photonic hydrogel functionalized with phenylboronic acid (PBA) for precise CGM. The fabrication of OF sensors involves a streamlined process, involving one‐step polymerization of PBA‐based hydrogel onto a commercial fiber tip and the integration of gold nanoparticles (AuNPs) via a simple dipping process. These sensors offer robust performance within the physiological glucose range (0–20 mm), exhibiting a remarkable 25% increase in transmission intensity and a 4 nm blue shift in the surface plasmon resonance with increasing glucose concentration. Additionally, there is a noticeable elevation in reflection intensity, affirming the sensor's suitability for remote sensing applications. These results are further validated using a green laser, underlining the method's reliability. The sensors exhibit a swift 30 s response time, followed by a 5 min saturation period, for all measurements. Practicality is demonstrated through smartphone readouts, utilizing the phone's photodiode to measure optical power changes concerning various glucose concentrations. These OF sensors hold great promise for CGM integration, enhancing diabetic management. [ABSTRACT FROM AUTHOR]

Colour vision disorders, pose challenges in perceiving and distinguishing specific colours. To address these challenges, technologies such as colour-filtering glasses and contact lenses have been developed. However, customisation of eyewear for individual patients remains a challenge. This research aims to design multifunctional contact lenses combining colour filtering and pH sensing capabilities for personalised colour vision correction. A pH-responsive, Neutral red dye-doped hydrogel was developed and optimised for the vat photo polymerization-based 3D printing process. A novel in-house multimaterial 3D printing technique was employed for printing lenses exhibiting both colour filtering and pH sensing capabilities. 3D printed samples contained outer radial rings, made from porous and pH-responsive polymer. The optically tunable dye-doped resin was also applied to the central part of the lenses to achieve customised wavelength blockage. The lenses demonstrate potential for customised colour vision correction and pH monitoring of the tear film. [ABSTRACT FROM AUTHOR]