What these devices do and why they matter for diabetes care

Smart contact lenses and glucose-sensing wearables are devices designed to track blood sugar levels continuously without fingerstick tests. A smart contact lens embeds a tiny sensor that reads glucose from tears; a glucose-sensing wearable (usually worn on the arm or abdomen) measures glucose from fluid under the skin. Neither requires you to prick your finger multiple times a day. Both send readings to your phone in real time, and some alert you when your glucose is too high or too low.

For people with type 1 diabetes or insulin-dependent type 2 diabetes, this matters because constant monitoring helps prevent dangerous blood sugar swings. Right now, most people either use fingerstick meters (which give one reading at a time) or continuous glucose monitors (CGMs) that are already on the market. The devices described here represent the next step—smaller, less invasive, and in some cases not yet approved for medical use.

The key difference from devices already available: smart contact lenses are still mostly in research phases, while some glucose-sensing wearables are closer to real-world use. Understanding where each one stands helps you know what might be an option for you in the near term versus what is still years away.

Key Takeaways

  • Smart contact lenses that measure glucose through tears are still in clinical testing and not yet available as medical devices you can purchase.
  • Glucose-sensing wearables that stick to your skin are further along in development than contact lenses and some versions are already in use or undergoing final testing.
  • These devices aim to replace or reduce fingerstick testing and work alongside or instead of current continuous glucose monitors.
  • Approval timelines vary: some wearables may reach the market within the next few years, while smart contact lenses are likely five to ten years away.
  • Insurance coverage and cost depend on whether a device is approved by the FDA and whether your plan covers it as a medical device or considers it experimental.

Smart contact lenses: how they work and where they stand

A smart contact lens is a thin piece of material worn like a regular contact lens, with an embedded sensor that detects glucose in your tears. The sensor sends a wireless signal to a receiver (usually your phone or a small wearable device) that displays your glucose reading. Some prototypes also include tiny LED lights that glow to alert you to high or low glucose without needing to look at your phone.

The main challenge is accuracy. Glucose levels in tears do not match blood glucose exactly, and tears change throughout the day based on hydration, eye health, and other factors. Researchers are still working on calibration—making sure the lens reading reliably reflects what your actual blood glucose is. This is why no smart contact lens has yet been approved by the FDA as a medical device.

Several companies and research teams are testing prototypes. Samsung, Mojo Vision, and academic labs have all announced projects, but most are still in early or mid-stage clinical trials. If development continues on schedule, some versions might reach the market in the mid-to-late 2020s, though timelines often shift. For now, smart contact lenses remain a future option, not something you can order today.

Glucose-sensing wearables: patches and implants closer to your skin

Glucose-sensing wearables measure glucose from interstitial fluid—the fluid that sits just under your skin—rather than from tears or blood. Most are worn as a patch on your arm or abdomen and stick to your skin for one to two weeks before you replace them. Some are designed to be implanted under the skin and last longer.

The FreeStyle Libre, made by Abbott, is already on the market in the United States and many other countries. It is a patch about the size of a large coin that you wear on your arm; you scan it with a reader or your phone to see your glucose. It does not send readings automatically—you have to check it—but it removes the need for fingersticks and stores up to eight hours of readings.

Other wearables are further along in testing. Eversense, made by Senseonics, is an implanted sensor that sits under your skin and sends readings wirelessly to a wearable transmitter you wear on your arm. It lasts up to 90 days before replacement. Dexcom's G7, another patch-based system, sends readings automatically to your phone every five minutes and has been available since 2022. These devices are already approved by the FDA and covered by many insurance plans.

Newer wearables still in development aim to last longer, be smaller, or work without needing a separate transmitter. Some companies are testing sensors that could last six months or more. The timeline for these newer versions varies, but several are expected to move toward FDA review within the next two to three years.

How these devices compare to what you can use now

If you use fingerstick testing today, both smart contact lenses and glucose-sensing wearables would reduce or eliminate the need to prick your finger. Wearables that are already approved (like FreeStyle Libre or Dexcom G7) do this now. Smart contact lenses would do it in the future, if they reach the market.

If you already use a continuous glucose monitor, the difference is mainly convenience and comfort. Current CGMs like Dexcom G7 and Eversense are already quite small and send readings automatically. Newer wearables aim to be even smaller, last longer, or require less frequent replacement. Smart contact lenses would be the smallest option of all—you would not need to wear anything on your body—but they are not yet available.

Cost and insurance coverage differ too. Approved wearables like Dexcom and FreeStyle Libre are covered by Medicare and many private insurance plans, though your out-of-pocket cost depends on your specific plan. Experimental devices in clinical trials are usually free to participants in the trial, but you cannot buy them outside the trial. Once a new device is approved, insurance coverage takes time to establish—sometimes months or years after FDA approval.

What the FDA approval process means for availability

Before any glucose-sensing device can be sold in the United States, it must be reviewed and approved by the FDA. The process typically takes one to three years, though it can be faster if the FDA grants expedited review. During this time, the device is tested in clinical trials with real patients to prove it is safe and accurate.

Once approved, a device can be sold and prescribed by doctors. Insurance companies then decide whether to cover it. Some cover it immediately; others wait for more real-world data or negotiate pricing first. This gap between approval and coverage can be weeks to months.

For smart contact lenses, the approval timeline is longer because the technology is newer and the FDA has less experience reviewing it. Glucose-sensing wearables are moving faster because the FDA has already approved similar devices and knows what to look for. This is why wearables are likely to reach you sooner than contact lenses.

Cost, insurance, and how to find out what is available to you

Approved glucose-sensing wearables vary in cost. FreeStyle Libre sensors cost roughly $60 to $100 per sensor (you replace it every two weeks), though insurance often covers most or all of this. Dexcom G7 sensors cost around $40 to $60 each (you replace it every ten days), and Eversense costs more upfront but lasts longer. Your actual out-of-pocket cost depends on your insurance plan, your deductible, and whether the device is on your plan's formulary (the list of covered items).

If you have Medicare, coverage for continuous glucose monitors is available if you meet certain criteria—usually, you must be on insulin therapy. Private insurance plans vary widely; some cover multiple options, others cover only one. The best way to find out what your plan covers is to call your insurance company directly and ask about continuous glucose monitors or glucose-sensing wearables by name.

For devices still in clinical trials, cost is usually zero—the research team or company running the trial pays for it. However, you must meet the trial's criteria and be willing to participate in testing, which may involve extra appointments or data collection. To find trials near you, search ClinicalTrials.gov and filter by "glucose monitoring" or "continuous glucose monitor" and your location.

Timeline: when each type of device might be available to you

Now (already approved and available): FreeStyle Libre (patch, scan-based), Dexcom G7 (patch, automatic readings), Eversense (implanted, automatic readings). These are prescribed by doctors and covered by many insurance plans.

Next 1 to 3 years (in late-stage testing or FDA review): Newer glucose-sensing wearables with longer wear time, smaller size, or improved accuracy. Several companies have devices in final clinical trials. Some may be approved and available by 2026 or 2027.

5 to 10 years (early research or mid-stage testing): Smart contact lenses. Multiple teams are working on them, but accuracy and manufacturing challenges remain. Even if a prototype works well in the lab, it typically takes several more years to move through clinical trials and FDA review.

These timelines are estimates based on current progress. Delays are common in medical device development, and breakthroughs can accelerate timelines. The best way to stay informed is to ask your doctor or endocrinologist what new devices are being tested and whether you might be a candidate for a trial.

What to ask your doctor about these devices

If you are interested in trying a newer glucose-sensing device, start by asking your doctor whether you are a candidate for one that is already approved. Your doctor can check your insurance coverage and help you understand the differences between available options. If you want to try something still in development, ask whether your doctor knows of any clinical trials recruiting in your area or whether they can refer you to a research center that runs them.

When talking to your doctor, be specific about what matters to you: Do you want to reduce fingersticks? Do you want automatic alerts? Do you prefer something you wear on your body or something less visible? Your answers help your doctor recommend the best option for your situation right now, and also help them know what to watch for as new devices become available.

Frequently Asked Questions

Can I use a smart contact lens if I already wear regular contacts?

Smart contact lenses are designed to replace your regular contacts, not to be worn alongside them. If you need vision correction, a smart contact lens would need to include your prescription. This is one of the engineering challenges researchers are still solving. For now, this technology is not yet available.

Do glucose-sensing wearables work if I have sensitive skin?

Some people develop skin irritation from the adhesive on patch-based sensors. If you have sensitive skin, talk to your doctor before starting a wearable. Some people use barrier films or rotate wear sites to reduce irritation. Implanted sensors like Eversense avoid skin contact but require a minor surgical procedure to insert and remove.

Will insurance cover a new glucose-sensing device right after it is approved by the FDA?

Not always. FDA approval and insurance coverage are separate processes. A device can be approved and available for purchase before insurance covers it. Coverage decisions can take weeks to months after approval. Ask your insurance company directly whether they plan to cover a specific device, and when.

What if I am in a clinical trial for a glucose-sensing device and it does not work for me?

You can usually withdraw from a trial at any time without penalty. Talk to the research team about your concerns. If the device is not working well, they may adjust settings, help you troubleshoot, or discuss whether continuing makes sense for you. You will not be charged for the device or visits related to the trial.

Are smart contact lenses or glucose-sensing wearables covered by Medicaid?

Coverage varies by state and by which device. Some state Medicaid programs cover FreeStyle Libre or Dexcom; others do not. Contact your state Medicaid office or your Medicaid plan directly to ask what glucose-sensing devices are covered. If a device is not covered, ask whether there is an appeals process or whether your doctor can request an exception.