Other groups are also developing continuous monitoring devices for glaucoma, including a team based in Lausanne, Switzerland, that's working to embed wireless microchip sensors in soft contact lenses. The researchers have developed and tested a wired version in humans and are now working on a wireless version.

One of the major obstacles in creating this type of device is designing a tiny but highly functional chip that uses very little power. Irazoqui's group has overcome this problem in part by designing the sensor to run on nanowatts rather than on microwatts. "We use a million times less power, which means we can get a million times more on the circuit," says Irazoqui, who declined to release further details until he presents the research later this month. The researchers will begin testing the implant in animals by December.

Shareef says that such a sensor, once available to patients and doctors, will not only provide better diagnosis for glaucoma, but it may also hold patients accountable for keeping track of their health. "You may have patients come in, and their pressure is wonderful in the office, but glaucoma is progressing rapidly," says Shareef. "It may be that patients are not taking their medications, and before they go to the doctor's, they take meds for two days, and the pressure will go down temporarily. But with a device like this, you can tell if they're cheating themselves."