Wearable tech is lightyears ahead of where it was when the Fitbit was introduced over a decade ago.

The market is projected to grow to $64B by 2024, as behemoths like Apple and Samsung add more health-tracking features that monitor everything from heart rate to sleep quality.

Neuroscience startups are pushing the tech into entirely new realms of medicine to:

Cure disease: Companies like Kernel and Flow Neuroscience (they’re hiring) are stimulating neurons in the brain to help clinicians treat diseases such as depression and Alzheimer’s.

Kernel is the brainchild of Bryan Johnson, founder of the online payments company Braintree. He initially wanted to build a memory prosthesis.

Regain mobility: Synchron  and BrainCo (they’re hiring) are working to help paralyzed patients regain movement.

Synchron’s device passes through cerebral blood vessels, allowing it to implant in the brain and allow patients direct brain control of mobility-assistive devices.

BrainCo, a product of the Harvard Innovation Lab, offers wearable headbands for education, fitness, and mind-controlled games and is developing a robotic prosthetic hand controlled by a user’s mind.

Sleep: Dreem helps people monitor their sleep with a head-mounted wearable that uses EEG electrodes to analyze brain activity. The company’s “bone conduction technology” emits subtle sounds intended to enhance the quality of sleep.

Track ovulation cycles: Ava’s (also hiring) fertility tracker helps women monitor their ovulation cycle, quality of sleep, stress levels, and heart rate.

Destress: Thync offers a wearable “pod” that attaches to the back of the neck and uses neurostimulation to combat stress and promote better sleep.

Optimize performance: Halo Neuroscience offers a brain-stimulating device that’s intended to enhance the efficiency of physical training by increasing plasticity in the brain prior to an activity. USA Cycling uses the device to train its cyclists.

Control computers: Neurable (they’re hiring) and Neuralink are developing ways for people to control software and devices using only their brain. Neurable uses a headset, while Elon Musk’s Neuralink is developing brain implants that directly link minds to computers.

If all of that isn’t sci-fi enough, consider: The cyborgs are coming.