This month marks one year since we lost my dad. It’s hard to believe that he’s already missed a full cycle of birthdays, holidays, and family get-togethers. My family is slowly learning how to adjust to life without him, although I don’t think things will ever feel normal again. I miss him every day.

My dad died from Alzheimer’s disease, which means that my family’s grief is far from unique. More people die from Alzheimer’s every year than from breast cancer and prostate cancer combined, and millions are suffering from the disease. Today, one out of every nine people aged 65 or older has Alzheimer’s disease. Too many families are being forced to watch their loved ones go downhill and disappear. It’s a brutal way to lose someone, and right now, there’s no way to stop or even slow down the decline.

I’ve written a lot on this blog about why I’m optimistic that new breakthroughs may someday soon let us substantially alter the course of the disease. One of the areas where we’ve seen the most progress over the past couple years is diagnostics.

The current process for diagnosing Alzheimer’s is a huge hurdle standing in the way of a breakthrough. If we’re going to find a game-changing treatment, we will need to test many different hypotheses, which would mean we need to conduct lots of clinical trials. That requires recruiting a lot of participants early enough in their disease that a drug might make a difference. But patients have to show signs of cognitive decline before they know to get tested—which means that their Alzheimer’s is already quite advanced—so many potential volunteers aren’t eligible. We need a cheap, non-invasive way to diagnose patients early before their symptoms get too bad.

The good news is that there are a number of promising new diagnostic tests in the pipeline. I partnered with the Alzheimer’s Drug Discovery Foundation to develop a philanthropic fund called the Diagnostics Accelerator several years ago with the hope that it would kickstart a bunch of new research. We were then joined by Jeff Bezos, MacKenzie Scott, the Dolby family, and several others to expand the effort. The first round of funding is expected to be completed by the end of the year, and many of the award recipients are already making terrific progress.

Some are working on diagnostics that may be available soon, like the simple blood test being developed at the University of Gothenburg in Sweden. Blood tests are the gold standard for diagnosing many diseases for a reason: they’re easy to administer and can be inexpensive to analyze. The test developed at Gothenburg looks for several indicators in the blood, including the presence of a protein called amyloid that can cause plaques in the brain. Samples are run through a common type of diagnostic platform developed by Roche, which means they can be analyzed at most labs.

Having an accessible blood test for Alzheimer’s would be huge. Many of us get our blood drawn once a year during our physical, and it’s easy to imagine a future where your results tell you how your brain is doing, just like how you currently get updates on the state of your heart. I’m hopeful this test will be available within the next year or two.

Other diagnostics in the pipeline use more unexpected methods to detect Alzheimer’s, like an eye test. Cecilia Lee—a researcher at the University of Washington here in Seattle—believes that your retina can provide a window into the brain. In 2018, she published a study showing that having an eye condition like glaucoma or macular degeneration doubles your risk for Alzheimer’s.

Ever since, she’s been looking for ways to use this link to diagnose Alzheimer’s. Cecilia and her colleagues are exploring different ways to scan your eyes for early signs of Alzheimer’s, including by using artificial intelligence to spot tiny irregularities that a human could never find. The UW team isn’t the only group hoping that the eyes are the key to a better diagnostic. Several companies including RetiSpec, Neurovision Imaging, and Optina Diagnostics are using new imaging techniques to look for amyloid plaques. We’re still years away from your annual eye exam including any test for Alzheimer’s, but I’m excited to keep following the research.

All of the tests I’ve mentioned require a trained medical professional and specialized equipment—but what if all you needed to assess your brain health was your smartphone? Several companies are working on highly sophisticated apps that might one day become diagnostics that are accessible to anyone with a phone or tablet. They have tremendous potential, although it’s too soon to tell whether any of them will pan out.

Cogstate is working on a test that looks like a series of mobile games. Each one evaluates a different function of your brain, like your ability to recognize emotions or focus on a task. A different company called Altoida is developing an app for your phone or tablet that uses augmented reality games to assess your cognitive abilities. (If you’ve ever played Pokemon Go, you’ve used AR.) If you score below a certain threshold on either test, your doctor could then order another diagnostic—like a blood test—to confirm whether you have the disease.

Nearly all of the tests I’ve mentioned are being supported by the Diagnostics Accelerator. The fund has invested in 25 candidates to date, and I’m hopeful that we have at least one game changer in the group. The Diagnostics Accelerator is also doing great work to make more samples and data available to researchers, which will hopefully speed up the time it takes to find a breakthrough.

If we want to stop Alzheimer’s, one of the biggest things we need to develop is a reliable, affordable, and accessible diagnostic. I think we’re close to having one, and the developments we’ve seen over the past couple years make me more optimistic than ever that we can one day stop Alzheimer’s. I can’t wait to see what new progress is unlocked thanks to better tests.