Because this is Optometric Management’s contact lens issue, I found myself reflecting on a prediction that has stayed with me for more than a decade. At an Optometric Glaucoma Society meeting in 2014, Dr. Robert N. Weinreb made a bold prediction. He suggested contact lenses that are capable of continuously monitoring intraocular pressure (IOP) would become the most disruptive advance in glaucoma care within 5 years. Twelve years later, we’re still waiting.

The irony is, as optometrists, we spend our careers identifying and quantifying visual field defects, but our management of glaucoma contains a significant blind spot. Consider this: If we examine a stable glaucoma patient 4 times a year and measure IOP once at each visit, we’re sampling pressure for roughly 4 seconds out of the 31,536,000 seconds in a year, and we often make treatment decisions based on those measurements. Four seconds.

Research shows that 24-hour IOP monitoring reveals clinically important pressure fluctuations that Goldmann applanation tonometry simply cannot capture during an office visit.¹ Nocturnal pressure elevations, transient IOP spikes, and overall pressure variability are all associated with glaucoma progression, but they frequently occur outside our examination room.^2,3 In some patients, we’re making decisions without access to IOP events that may be driving disease progression.

So Why Aren’t Our Patients Already Wearing Smart Contact Lenses?

The answer isn’t a lack of innovation. Multiple sensing technologies are under active investigation, but translating promising laboratory research into a clinically practical device has proven difficult. Challenges remain, including maintaining measurement accuracy throughout a full day of wear, ensuring long-term corneal safety, preserving sensor performance during sleep, and validating these devices in larger clinical trials. Until those hurdles are overcome, FDA approval remains out of reach.

Even so, perhaps we’re asking too little of these devices. The future may also be theranostic contact lenses that both detect elevated pressure and respond by treating it automatically. Several recent engineering advances suggest this may occur soon.

One investigational smart lens incorporates gold hollow nanowires that continuously monitor IOP while wirelessly triggering the release of timolol to lower IOP in animal models.⁴ Another design combines a capacitive pressure sensor with iontophoresis, which allows the lens to detect pressure elevations and actively deliver glaucoma medication when needed.⁵

Most exciting is the newest generation of battery-free, all-polymer microfluidic theranostic contact lenses. Rather than relying on electronics, these lenses contain embedded microchannels with preset pressure thresholds. When IOP exceeds those thresholds, the lens automatically releases medications such as timolol or brimonidine. In rabbit models of ocular hypertension, this technology has achieved IOP reduction that is at least comparable to conventional topical therapy.⁶

These systems remain experimental and have only been evaluated in animal studies. Significant engineering and clinical and regulatory hurdles remain before they become part of everyday practice. Still, the potential is great.

The future of glaucoma management may not be simply measuring IOP more often. It may be continuously understanding IOP and ultimately allowing the technology to respond automatically and treat when pressure rises.

When that day arrives, we’ll finally eliminate glaucoma’s 4-second blind spot. Perhaps we will give our patients a therapy that lives up to our best intentions: one that is always watching, measuring, ready to treat and, ultimately, preserve vision.OM

References:

1. Monsálvez-Romín D, Martínez-Albert N, García-Domene MC, Ortí-Navarro S. Current and emerging technologies for continuous intraocular pressure monitoring in the control of glaucoma progression: a scoping review. J Clin Med. 2025;14(24):8795. doi:10.3390/jcm14248795

2. Konstas AG, Kahook MY, Araie M, et al. Diurnal and 24-h intraocular pressures in glaucoma: monitoring strategies and impact on prognosis and treatment. Adv Ther. 2018;35(11):1775-1804. doi:10.1007/s12325-018-0812-z

3. Gaboriau T, Dubois R, Foucque B, Malet F, Schweitzer C. 24-hour monitoring of intraocular pressure fluctuations using a contact lens sensor: diagnostic performance for glaucoma progression. Invest Ophthalmol Vis Sci. 2023;64(3):3. doi:10.1167/iovs.64.3.3

4. Kim TY, Mok JW, Hong SH, et al. Wireless theranostic smart contact lens for monitoring and control of intraocular pressure in glaucoma. Nat Commun. 2022;13(1):6801. doi:10.1038/s41467-022-34597-8

5. Yang C, Wu Q, Liu J, et al. Intelligent wireless theranostic contact lens for electrical sensing and regulation of intraocular pressure. Nat Commun. 2022;13(1):2556. doi:10.1038/s41467-022-29860-x

6. Cai Y, Zhang C, Dang P, et al. Real-time intraocular pressure monitoring and responsive drug release in preclinical models by an all-polymer smart contact lens. Sci Transl Med. 2026;18(844):eads9541. doi:10.1126/scitranslmed.ads9541

Mike Cymbor, OD, FAAO is director of the Glaucoma Institute of State College and the lead OD at Nittany Eye Associates in State College, Pennsylvania.