In glaucoma care, intraocular pressure (IOP) is the main modifiable factor you and your doctor try to control, because pressure fluctuations or spikes can worsen optic nerve damage. Traditional office visits give only occasional “snapshots” of IOP, but your pressure may vary by hour, day, or posture.

Thanks to advances in home tonometry, you may now have the option to monitor your IOP outside the clinic. Home measurement can help detect pressure spikes you’d otherwise miss, better inform treatment, and possibly allow earlier adjustment of therapy. 

Below is what you should know, including how it works, when it helps, its accuracy (with caveats), and how to use it safely and effectively in partnership with your eye doctor.

Types of Home IOP Monitoring

Several devices and technologies are now available (or in development) to help you measure eye pressure outside of the clinic:

• Rebound tonometers

• • • The most common self-use option.
    • Use a small probe that briefly touches the cornea to estimate IOP.
    • Do not require numbing drops.
    • Examples: iCare Home and the newer iCare Home2, widely studied for patient use.
      
  • Tono-Vera (cleared in 2024)
    • A rebound tonometer with built-in alignment guidance using a camera.
    • Designed to help patients position the device correctly for more consistent readings.
      

• Emerging technologies

• • Smart contact lenses that measure pressure changes continuously.
  • Implantable micro-sensors placed inside the eye for ongoing monitoring.
  • Still in research or early clinical use, not yet widely available.

Key takeaway: Today, most patients who monitor their eye pressure at home use rebound tonometers, such as the iCare Home. Newer tools are making self-testing easier, and continuous monitoring technologies may soon expand options.

Accuracy, Reliability & Limitations

Home devices are not perfect, and you need to understand their strengths and limitations. In a recent study of 104 glaucoma patients using iCare Home2, self-measured IOP had good reliability and repeatability, with average difference from Goldmann applanation tonometry (the clinical standard) of only –0.28 mmHg (±1.57 mmHg) in many cases.

However, agreement varies depending on corneal thickness, alignment errors, and user technique. Some patients (up to ~27 %) may struggle to use home devices properly. Additionally, rebound tonometers tend to underestimate very high pressures and overestimate very low pressures relative to Goldmann. 

Therefore, it is recommended to use home measurements as a supplement, not a replacement, for your clinic IOP checks and other tests (visual fields, OCT).

When and How Often to Monitor

When your eye doctor prescribes home monitoring, common protocols involve measuring IOP multiple times per day (morning, midday, evening) over a few days or a week. This helps capture daily fluctuations and spikes you might miss in the clinic.

Pick consistent times relative to your medication schedule (for example, before drops, two hours after) and posture (sitting upright, etc.). Note the time, your eye (right or left), and your position each time.

Practice runs under supervision, in the clinic or via telehealth, until you’re confident in proper alignment, positioning, and obtaining reliable readings.

Safety, Training & Best Practices

Before you begin, have training from your eye care team. Mistakes in alignment, blinking, or probing too hard can lead to error or discomfort. Use the device only as instructed.

Record every measurement carefully (time, value, any notes). Many home tonometers are compatible with apps or software, allowing you to export data and share it with your physician. 

If you notice a sudden, high spike (especially one that is significantly above your target range), contact your provider promptly. Don’t attempt to self-adjust medications without guidance.

Using Home IOP Data with Your Doctor

Your ophthalmologist can review your home IOP curve trend over the day or week, rather than relying on a snapshot from a single visit. This may reveal spikes or fluctuations that require adjustments in treatment.

In fact, in published cases, home IOP monitoring led clinicians to intervene earlier, e.g., adding drops or performing laser treatment, in patients who otherwise appeared “stable” during clinic visits.

Additionally, some telemedicine models incorporate home tonometry data into remote glaucoma follow-ups, potentially reducing the need for in-office visits. 

However, your provider should interpret the data in context (corneal thickness, measurement conditions) and correlate with imaging and visual field results.

In Sum

Monitoring eye pressure at home with devices like iCare Home/Home2 or others provides you and your care team with a richer picture of your IOP behavior over time. While not perfect, these devices can help detect spikes, guide therapy, and improve your disease control. Always undergo training, document carefully, and use the data in partnership with your ophthalmologist, not as a substitute.

Sources

• EyeWorld. Home IOP monitoring influences clinical care and glaucoma research (2024). eyeworld.org 
• Ophthalmology Glaucoma. Reliability of Self-Monitoring of Intraocular Pressure With iCare Home2 by Patients With Glaucoma (2025). journals.lww.com 
• Glaucoma Physician. An Update on Novel Devices to Measure Intraocular Pressure (2024). glaucomaphysician.net
• Glaucoma Today. Continuous IOP Monitoring (2024). glaucomatoday.com
• Ophthalmology Glaucoma. Telemedicine and Home Tonometry for Glaucoma Care (2024). ophthalmologyglaucoma.org 

To ensure that we always provide you with high-quality, reliable information, The Glaucoma Community closely vets all sources. We do not, however, endorse or recommend any specific providers, treatments, or products, and the use of a given source does not imply an endorsement of any provider, treatment, medication, procedure, or device discussed within.