. 2024 Oct 5;5(6):100710. doi: 10.1016/j.xinn.2024.100710
Guang Yao
1,2,5,∗, Peisi Li
1, Mingpeng Liu
1, Feiyi Liao
3,∗∗, Yuan Lin
1,2,4,∗∗∗
PMCID: PMC11541485PMID: 39512377
Main text
Smart glasses are multifunctional devices designed to replicate the capabilities of smartphones, offering entertainment, fitness tracking, and various other features. However, currently available head-mounted devices tend to be large and heavy, leading to discomfort and diminished immersion. In contrast, the advent of smart contact lenses (SCLs) signifies a significant advancement beyond mere entertainment, representing a groundbreaking intersection of traditional eyewear and advanced scientific innovation. Essentially, SCLs act as catalysts for turning science fiction (sci-fi) into reality. These lenses are not merely medical aids but also technological marvels, ushering intelligent medical care and artificial intelligence into everyday routines. Equipped with sophisticated sensors and actuators, SCLs have the potential to revolutionize eye health, facilitating disease detection, targeted treatment, and even artificial vision. Their rapid development promises a comprehensive eye health management and personalized medicine approach. Furthermore, SCLs signal the dawn of a new era in human-computer interactions within augmented reality (AR) and virtual reality (VR) experiences, allowing for direct engagement with the digital landscape. They empower users by providing real-time access to information, online connectivity, and tailored services, enhancing personal and professional experiences with limitless opportunities. Additionally, as gateways to this digital environment, SCLs drive the metaverse’s evolution, unlocking the benefits and conveniences of the virtual world (Figure1).
Figure1.
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SCLs progress on personalized healthcare
The eye, revered as one of the most vital sensory organs for earthly creatures, serves as a natural open window for interactions between humans and the outside world. Within the intricate structures of the eye reside numerous physiological indicators and metabolic biomarkers vital for a comprehensive health assessment. Research in this field has progressed steadily since the introduction of the SCL concept in 2007, which aimed to measure intraocular pressure non-invasively. The momentum of this research significantly increased in 2014 following Google’s announcement of its SCL initiative, which generated considerable interest and a subsequent rise in related research papers from 2017 onward.1 These innovative lenses are designed to adhere comfortably to the eye, allowing for continuous and non-invasive monitoring of various physical and biochemical signals, including intraocular pressure, glucose levels, electroretinograms, and eye movements over extended durations. This capability is instrumental in the early detection, prognosis, and management of ocular conditions. Moreover, interdisciplinary collaborations are advancing the development of sophisticated SCLs, with a focus on enhancing sensitivity, enabling wireless signal transmission, and incorporating personalized and ergonomic design features.
Aside from their roles in detection and diagnosis, SCLs are emerging as pivotal catalysts for innovative treatment modalities in ophthalmology.1,2 By leveraging targeted drug delivery and physical interventions, they provide targeted therapeutic solutions for a spectrum of eye ailments, thereby revolutionizing the landscape of eye care. Traditional methods, such as eye drops and ointments, face challenges in penetrating anatomical and physiological barriers, underscoring the necessity of SCL-based drug delivery systems. Cutting-edge SCL-based drug delivery systems are engineered to encapsulate drugs efficiently, deliver precise doses, ensure optimal bioavailability, and improve patient adherence, which uplifting trial results will undoubtedly boost the advances in treating ocular ailments. The integration of diagnostic and therapeutic capabilities enhances the efficacy of ocular management and pavesthe way for advanced electronic platforms focused on eye health and personalized medicine. In an era characterized by unprecedented technological advancements, SCLs are poised to redefine eye care, ushering in precision medicine that intersects with proactive health management.
SCLs for artificial vision
Before delving into the intersection of sci-fi and reality concerning SCLs for artificial vision, it is essential to investigate their practical applications, particularly in addressing visual impairments characterized by degeneration and temporal variability. Myopia, commonly known as nearsightedness, is a prevalent refractive error that affects individuals across various age demographics. Its global prevalence has been steadily rising, projected to surge from 22% in 2000 to a staggering 52% by 2050 according to the World Health Organization. Although traditional contact lenses were first developed in the late 19th century primarily for vision correction, they do not adequately address severe visual impairments or blindness. In sci-fi, one often encounters the fantastical replacement of human organs with artificial counterparts post-injury. However, "artificial eyes" involving the retina, optic nerve, and visual center remain significant hurdles. Much like the implausibility of an "artificial brain," the concept of artificial vision encounters similar obstacles. Consequently, when diseases affect the visual pathway beyond the retina, resulting in irreversible visual impairment, treatment options become limited. Retinal prostheses represent a significant advancement in artificial vision technology. Recent simulation and experimental studies have demonstrated that SCL-based ultrasound stimulation effectively activates retinal neurons, producing visual signals transmitted to the brain via the optic nerves. This reflects the potential for a non-invasive ultrasound retinal prosthesis.3 Despite strides in interdisciplinary technology, replicating the intricacies of human vision remains a profound scientific endeavor.
SCLs for ET, AR, and VR
Eye tracking (ET) technology is crucial for analyzing visual attention and cognitive processes, and it has significant implications for human-computer interactions and medical applications. Recent innovations in SCLs, which utilize various ET principles, have led to the development of portable biorecognition systems. For instance, Zhu etal. have created a compact, imperceptible, wireless SCL designed for real-time ET and eye-machine interactions.4 Their chip-free, battery-free design features four passive radio frequency tags with distinct frequencies and achieves an angular accuracy of <0.5°, exceeding the visual range of the central fovea. This SCL is anticipated to enhance the methodologies of ET techniques while advancing the field of human-machine interaction technology.
VR and AR are revolutionizing our perception and interactions with digital content, bridging the divide between virtual imagery and the physical environment. Nevertheless, the current head-mounted displays for AR/VR are often cumbersome, which detracts from both immersion and comfort. SCLs represent a convergence of advanced technology and wearable innovation, with the potential to revolutionize AR and VR experiences. Equipped with micro-displays that project images directly onto the wearer’s retina, these lenses can provide navigation directions, notifications, and other visual information directly within the user’s field of vision, potentially exceeding the capabilities of smartphones and offering a more immersive and intuitive interface compared to traditional screens. A significant milestone was achieved in 2019 with the development of AR SCLs by Mojo Vision, highlighting the trend toward compact display technologies. Researchers are proposing the integration of miniature cameras and displays withinlenses to overlay information onto the wearer’s eyes, utilizing advancements in embedded vision to recognize objects and individuals. SCLs present unprecedented opportunities in human-computer interactions and experiential computing, transcending the boundaries between reality and imagination across various domains.
Evolution directions and challenges
“Sci-fi is the reality of the future” encapsulates that sci-fi narratives serve as blueprints for societal, technological, and cultural evolution. SCLs, which facilitate natural and seamless human interactions, are revolutionizing health monitoring and disease management by fostering a personalized connection among individuals, health management systems, artificial vision technologies, and AR/VR experiences.5 Nevertheless, despite these advancements, SCLs encounter significant challenges in evolving into robust and intelligent systems. For example, the pursuit of multifunctional integration within a single-layer SCL may lead to increased spatial occupancy, resulting in trade-offs between user comfort and functional density. To address this challenge, three-dimensional multi-layer vertical stacking and interconnection integration techniques may present viable solutions, enhancing functional density, improving device performance, and reducing overall device size. Furthermore, the implementation of closed-loop interaction technologies that integrate medical devices with artificial intelligence can facilitate dynamic adjustments to treatment strategies, thereby improving the precision and efficacy of human-machine interactions. Additionally, long-term safety and ethical considerations regarding privacy represent critical concerns for the next generation of SCLs. It is imperative for researchers and policymakers to investigate safer materials and designs as well establish protocols and regulations aimed at mitigating risks associated with potential damage and unethical applications. By proactively addressing these challenges, we can optimize the societal benefits of SCLs while minimizing the risks and unintended consequences associated with their widespread implementation, thereby underscoring the transformative potential of human creativity in shaping the future.
Acknowledgments
This work was supported by the National Natural Science Foundation of China (U21A20460, 62422104, 62371115, and 52021001), the Science and Technology Major Project of Tibetan Autonomous Region of China (XZ202201ZD0001G), the Science and Technology Department of Sichuan Province (2024NSFSC0234), and the Medico-Engineering Cooperation Funds, Fundamental Research Funds for the Central Universities (ZYGX2021YGLH002).
Declaration of interests
The authors declare no competing interests.
Published Online: October 5, 2024
Contributor Information
Guang Yao, Email: gyao@uestc.edu.cn.
Feiyi Liao, Email: david3349@163.com.
Yuan Lin, Email: linyuan@uestc.edu.cn.
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