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Transforming contact lenses into therapeutic and diagnostic devices: A comprehensive review
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Received: ,
Accepted: ,
How to cite this article: Mangla L. A comprehensive review: Transforming contact lenses into therapeutic and diagnostic devices. J Ophthalmic Res Pract. 2026;4:9-13. doi: 10.25259/JORP_5_2026
Abstract
Recent changes in material sciences, optical engineering, and biomedical technology have greatly transformed contact lens design and clinical utility. Modern contact lenses are no longer limited to refractive correction only but have evolved into multidirectional devices that enhance ocular health, comfort, and therapeutic efficiency. The introduction of hydrogel silicone materials has greatly improved oxygen permeability, thus reducing hypoxia-related complications and enabling extended wear. In parallel, scleral lenses have expanded clinical applications, particularly in the management of irregular corneas and ocular surface disorders by providing both optimal correction and continuous hydration. Emerging technologies such as drug-eluting lenses and smart contact lenses offer innovative solutions for sustained drug delivery and real-time physiological monitoring. These developments correctly position contact lenses as advanced biomedical platforms with increasing relevance in modern medicine. This review critically examines recent advances in contact materials design innovations and technological integration, along with their clinical implications and future potential.
Keywords
Contact lenses
Drug-delivery
Dry eye
Keratoconus
Scleral lens
Silicone hydrogel
Smart lenses
INTRODUCTION
Contact lenses represent one of the most widely utilized modalities in optometry and ophthalmology, serving purposes that extend beyond simple vision correction to include therapeutic and cosmetic applications. With a global user base exceeding 200 million individuals, their adoption continues to grow, driven by the increasing prevalence of refractive errors and heightened expectations for comfort, safety, and convenience. However, despite their widespread use, contact lenses are associated with several complications, including corneal hypoxia, dry eye symptoms, microbial keratitis, and inflammatory responses. These issues can greatly affect patient health and reduce patient compliance, especially among individuals requiring prolonged or continuous wear.[1-4]
To overcome these limitations, extensive research has focused on improving lens materials and design characteristics, especially in terms of oxygen transmissibility, surface wettability, and resistance to microbial addition. The transition from rigid polymethyl with methylene hydrogen and subsequently silicon hydrogen materials represents a critical milestone in enhancing both safety and comfort. Now, material improvements and modern contact technology have expanded to incorporate drug delivery capabilities, biosensing systems, and customized designs tailored to complex ocular conditions. These innovations reflect a direct shift in which contact lenses are increasingly viewed as integrated platforms for diagnosis, monitoring, and treatment rather than solely as optical devices.[5-7]
RECENT ADVANCES IN CONTACT LENS TECHNOLOGY
The evolution of contact lens materials has been central to improving both clinical outcomes and patient experience. Early lenses made from polymethyl methacrylate provided excellent optical clarity and durability, but lacked oxygen permeability, often resulting in corneal hypoxia and associated complications. The introduction of hydrogel materials marked a significant advancement, as their water-containing structure allowed limited oxygen transmission while improving comfort and flexibility. However, these materials were still insufficient for extended wear applications.[1-3]
The development of silicon-hydrogen lenses represents a major breakthrough in contact lens technology. By combining the high oxygen probability of silicone with the hydrophilic properties of hydrogel, these lenses significantly enhance oxygen delivery to the cornea.[4] Hence, reducing the risk of hypoxia-related complications such as corneal edema, neovascularization, and epithelial compromise. Silicon-hydrogen lenses incorporate additional innovations such as surface modification technology and water gradient design, which improve tear stability and reduce friction between the lens and ocular surface.[8] The integration of microbial coating, ultraviolet blocking agents, and a moisture retention system has contributed to improved safety, reduced infection risk, and enhanced wearer comfort, especially in patients with dry eye or sensitive ocular surfaces. Table 1[1,2,4-6,9-13] shows a detailed comparison of these polymer material properties and Table 2 further highlights these advancements.
| Silicone hydrogel[1,2,4] | High oxygen permeability (up to 5×more than hydrogels) - Soft and flexible - Moisture retaining technologies (e.g., Hydra Clear Plus, Smart Shield) |
Daily and extended wear - Correction of myopia, hyperopia, astigmatism, and presbyopia - Suitable for active lifestyles |
May cause dryness in sensitive eyes - Prone to deposit buildup - Not ideal for silicone-sensitive users |
| Drug-eluting lenses[5,6] | Embedded pharmaceutical agents - Sustained and controlled drug release - Enhanced bioavailability (up to 50%) |
Glaucoma (e.g., timolol, bimtoprost) - Allergic conjunctivitis (e.g., ketotifen) -Post-surgical inflammation |
Still experimental in many regions - Limited commercial availability - Risk of corneal toxicity or discomfort |
| Scleral lenses[9-13] | Rigid gas permeable material - Vaults over the cornea, rests on the sclera - Creates a fluid reservoir for hydration and protection |
Irregular corneas (e.g., keratoconus, post-surgical ectasia) - Severe dry eye (e.g., Sjogren syndrome) - Ocular surface disease |
Requires complex fitting and customization - Higher cost - Longer adaptation period for new users |
| Material classification | Polymer examples | Average water content (%) | Oxygen transmissibility (Dk/t) | Average modulus (MPa) | Primary clinical limitation |
|---|---|---|---|---|---|
| Traditional hydrogel | pHEMA, etafilcon A | 38–58 | 20–30 | 0.3–0.5 | Hypoxia, low oxygen permeability |
| 1st gen silicone hydrogel | Lotrafilcon A, balafilcon A | 24–36 | 110–175 | 1.1–1.5 | Mechanical stiffness, lipid deposition |
| 3rd gen silicone hydrogel | Comfilcon A, senofilcon A | 38–48 | 120–160 | 0.7–0.8 | Wetting angle stability over 12 h |
| Water-gradient SiHy | Delefilcon A | Core: 33, surface: >80 | 156 | Core: 0.7, surface: ~0.01 | Manufacturing complexity, cost |
FUTURE INNOVATIONS IN CONTACT LENS DESIGN
Silicone hydrogel lenses
Silicone hydrogel lenses have become the standard in modern contact lens practice due to their superior oxygen transmissibility and enhanced physiological compatibility. These lenses support extended wear without reducing corneal health, making them suitable for individuals with high refractive errors or those requiring long-duration lens use. To maintain adequate oxygen supply, advancements in surface treatments and internal wetting agents have improved comfort by minimizing dryness and irritation. As a result, silicone hydrogel lenses have greatly improved patient compliance and expanded the range of clinical indications for contact lens wear.
Scleral lenses
Scleral lenses represent a specialized category of rigid gas-permeable lenses designed to vault over the cornea and rest on the sclera. This unique design creates a fluid-filled reservoir between the lens and the ocular surface, providing continuous hydration and protection. Scleral lenses are beneficial in patients with irregular corneal topography, such as those with keratoconus, post-surgical ectasia, or corneal scarring. To improve visual acuity, these lenses play a therapeutic role in managing severe dry eye and ocular surface disease by maintaining a stable tear environment and shielding the cornea from external irritants.[9-13] Advances in imaging technologies, including corneal topography and scleral profilometry, have further enhanced the customization and fitting accuracy of scleral lenses, leading to improved patient outcomes and reduced chair time.
Specialty lens designs
Material advancements and innovations in lens design have enabled the development of specialized lenses tailored to specific refractive and clinical needs. Toric lenses provide precise correction for astigmatism through stabilization mechanisms that maintain consistent orientation on the eye, whereas multifocal lenses address presbyopia by incorporating multiple focal zones to allow clear vision at varying distances. Orthokeratology lenses, which are worn overnight to reshape the cornea temporarily, offer a non-surgical approach to myopia correction and have gained particular attention for their role in slowing myopia progression in pediatric populations.[14] These specialized designs highlight the increasing sophistication of contact lenses in addressing diverse visual and therapeutic requirements.
Drug-delivering contact lenses
Drug-eluting contact lenses represent a significant advancement in ocular pharmacotherapy by addressing the limitations of conventional eye drop administration.[5,6] Traditional topical medications suffer from poor bioavailability due to rapid tear turnover, blinking, and nasolacrimal drainage, resulting in less-than-optimal drug absorption. Drug-delivering contact lenses enable sustained and controlled release of therapeutic agents directly to the ocular surface, thereby enhancing drug retention time and therapeutic efficacy.[15-17] These lenses incorporate medications within the lens matrix or surface coatings, allowing for gradual diffusion over an extended period.
Clinical applications of drug-eluting lenses include the management of glaucoma, allergic conjunctivitis, and postoperative inflammation.[7] By reducing the need for frequent dosing and improving drug bioavailability, these systems enhance patient compliance and minimize systemic side effects. Ongoing research is focused on optimizing drug loading techniques, release kinetics, and biocompatibility to facilitate broader clinical adoption.
SMART AND BIOSENSING CONTACT LENSES
The integration of microelectronics and biosensing technologies into contact lenses has led to the development of smart lenses capable of real-time physiological monitoring. These lenses are designed to detect and measure parameters such as intraocular pressure, tear glucose levels, and biochemical markers associated with ocular and systemic diseases.[13,18] By providing continuous, noninvasive monitoring, smart contact lenses have the potential to significantly improve disease management, particularly in conditions such as glaucoma and diabetes.
Biosensing contact lenses further extend diagnostic capabilities by detecting inflammatory markers, proteins, and other molecular indicators present in tear fluid. Advances in nanotechnology and wireless communication have enabled these lenses to transmit data to external devices, facilitating remote monitoring and personalized treatment strategies. Although still in developmental stages, these technologies represent a transformative step toward precision medicine in eye care.
FUTURE DIRECTIONS
The future of contact lens technology is increasingly focused on multifunctionality, personalization, and integration with digital health systems. Emerging innovations include stimuli-responsive lenses capable of releasing drugs in response to environmental triggers such as pH or temperature, as well as hybrid lenses that combine vision correction, drug delivery, and biosensing capabilities within a single platform. Advances in three-dimensional printing are enabling the production of highly customized lenses tailored to individual ocular anatomy, thereby improving fit and comfort.
The integration of artificial intelligence and internet-connected systems is expected to enhance predictive diagnostics and enable real-time clinical decision-making. Research into gene therapy-compatible lenses is also gaining momentum, offering a novel, non-invasive approach to treating genetic and degenerative ocular diseases. These developments highlight the expanding role of contact lenses as versatile tools in modern healthcare.
CLINICAL IMPLICATIONS
Advancements in contact lens technology have significantly improved clinical outcomes by enhancing safety, comfort, and therapeutic effectiveness. Improved oxygen permeability reduces the risk of hypoxia-related complications, while advanced designs allow effective management of complex ocular conditions. Drug-delivering lenses offer a practical solution to compliance issues associated with traditional therapies, and smart lenses provide new opportunities for early diagnosis and continuous monitoring.
The successful implementation of these technologies depends on appropriate patient selection, accurate lens fitting, and strict adherence to hygiene practices. Eye care professionals must remain informed about evolving technologies to optimize patient outcomes and minimize the risk of complications.
CONCLUSION
Contact lenses have undergone a remarkable transformation from basic vision correction devices to advanced biomedical platforms that play a critical role in modern eye care. Innovations in material science, particularly the development of silicone hydrogel lenses, have significantly improved oxygen delivery and wearer comfort, while specialized designs such as scleral lenses have expanded therapeutic applications for complex ocular conditions. The emergence of drug-eluting and smart contact lenses further underscores the shift toward multifunctional systems capable of delivering targeted therapy and enabling real-time physiological monitoring.
Despite these advancements, challenges related to cost, accessibility, long-term safety, and regulatory approval continue to limit widespread adoption. Addressing these barriers will require sustained research efforts and collaboration across disciplines. As technology continues to evolve, contact lenses are expected to become increasingly integral to personalized and preventive eye care, offering innovative solutions that extend far beyond traditional vision correction.
Author contributions:
LM: Solely responsible for conceptualization, manuscript writing, review, editing, and approval of the final version.
Ethical approval:
Institutional Review Board approval is not required.
Declaration of patient consent:
Patient’s consent is not required as there are no patients in this study.
Conflicts of interest:
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation:
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript, and no images were manipulated using AI.
Financial support and sponsorship: Nil.
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