In the 1983 movie Never Say Never Again, the bad guy goes under the knife to  match his retina to the US president’s so that he can fool a retinal scanner  and gain control of nuclear weapons.

And of course, James Bond manages to save the day, while also being exceedingly dashing. We have retinal scanners in real life, too, though it turns out that as  spy gadgets, they kind of suck.

Instead, this James Bond tech has found  its way into your eye doctor’s office, where it has the potential to improve  your overall health for years to come. Here’s how. [♪ INTRO] The retina is the very back of the eye,  and it’s home to your rods and cones, the receptors that turn light into  electrical signals for the brain to process. Tons of blood vessels criss-cross it, providing  oxygen and energy for it to do its job.

Because structures in the eye need to be  transparent for light to pass through, doctors can see the retina using completely  non-invasive methods with the right tools. If you’ve ever had an optometrist  put drops into your eyes and give you those ridiculous  sunglasses when you leave, it’s because they were trying  to take a gander at your retina. Being able to see those structures gives  them a sense for how healthy the eye is.

But the tech of Bond movies might spell  the end of those annoying drops forever. Way back in 1926, the first commercially  available retinal camera was able to image about 20 degrees of the retina, which  is helpful, but a pretty small slice. Since the structure of the retina is unique  to the individual, spy movie writers – and real spies – pictured using this technology  as a sophisticated identification device.

So they do work, but it turns  out they suck to actually use. Among other things, having a  thing you stick your eye close to is kind of asking for pinkeye. Instead, devices similar to these are  seeing way more use in healthcare, and are working their way  into optometrists’ offices.

And they’re improving fast. Anything that allows for more  than 100 degrees of visibility is considered ultra-widefield retinal imaging. The most state-of-the-art instrument  available at the time we’re writing this lets doctors see 200 degrees of the  retina, or 82% of it, in a single image.

Being able to see more of the outer  part of the retina, not just the center, gives us even more information about our health. And these fancy cameras have another advantage: Cameras take pictures. Instead of just allowing doctors to see  what your retina looks like right now, they can save previous images in your  file and compare changes over time.

So you can… Eye Another Day. Now, better retinal imaging is obviously  good news for diagnosing eye diseases. Some, like glaucoma, don’t have early symptoms.

In fact, half of people with  glaucoma don’t realize they have it. And treatment for glaucoma can’t restore vision, but it can keep vision loss from getting  any worse, so early detection is essential. Studies are indicating that ultra-widefield  imaging can show subtle changes in the retina that are  indicative of early glaucoma, letting doctors catch it  earlier than they could before.

But the diagnosing that ultra-widefield  retinal imaging systems can do isn’t… For Your Eyes Only. It can give us information about  diseases in other body systems, too. For example, diabetes can  cause changes in the retina, known as diabetic retinopathy.

High blood sugar can damage  blood vessels all over the body, causing them to leak or bleed. And the retina has plenty of blood vessels. One risk factor for the progression of  diabetic retinopathy is having more lesions toward the edges of the retina, which  ultra-widefield imaging allows us to see.

Which means that about 20% of the time,  using ultra-widefield imaging ends up diagnosing diabetic retinopathy as more  severe than traditional screening methods. But more than that, between 10 and 20 percent  of adult diabetes cases are undiagnosed. So it’s possible that optometrists  may be able to use retinal imaging to catch diabetic retinopathy in patients who haven’t been diagnosed with  diabetes in the first place.

Making the eye doctor a pretty unexpected way to identify those people  and make sure they get care! The retina can also tell us about heart health. The tiny blood vessels in the retina  are related to the blood vessels in the rest of the body.

Which means they can give us a… View to a Kill-er: Cardiovascular disease. Changes in retinal blood  vessels are associated with risk of cardiovascular disease, especially stroke. In this case, imaging the retina  provides a few new opportunities.

For one thing, it can provide more fine-grained  detail about a patient’s level of risk, and that helps doctors plan accordingly. For another, the photography component  means that images can more easily be compared over time to see if there are changes. And maybe most beneficially, some people  may be more likely to go to a yearly optometrist visit than a general checkup,  so if this test was included in a standard eye exam, more people would be getting  screened for cardiovascular disease.

Our eyes can tell us about our brains, too. The eye is the only part of the  central nervous system that you can see with simple methods, so this kind of  imaging shows a lot of promise for studying and diagnosing central nervous system disorders. Like Alzheimer’s disease.

Just like Alzheimer’s causes a  loss of neurons in the brain, it can also cause a loss of the neurons  that connect the retina to the brain. Retinal imaging can determine  the thickness of the retina, specifically the layer that holds all  those neurons and their projections, which can tell us whether  those neurons are dying off. The thing is, we’re currently not  great at diagnosing Alzheimer’s while a patient is still alive.

One estimate is that 50 to 80% of  Alzheimer’s cases can go unrecognized. So just like with cardiovascular disease,  ultra-widefield retinal imaging could be easier, cheaper, and more available  than any of our other diagnostic tests, allowing more people to be  diagnosed and treated sooner. So while ultra-widefield retinal  imaging was kind of a flop for unlocking your apartment or boarding a plane, it shows a lot of promise for monitoring  not just eye health, but whole body health.

It allows us to establish  baselines and monitor patients, so small changes can be caught early. And lots of people wear glasses, so lots of people go to the  eye doctor on a regular basis. It’s actually hard to overstate how huge  that is, like, doctors can’t help people they don’t see, so having your  eye doctor being able to screen for this stuff should amount to  getting this stuff found and treated.

We’re constantly learning more about  how the eye is involved in health, and as these devices appear  in more optometrists' offices, hopefully we’re only at the beginning  of retinal imaging helping people… Live and Let Eye… Sorry. Thanks to all our patrons for  helping make this video possible, but especially this month's president  of science, McLaren Stanley, who was officially cooler than  at least half of the Bonds. Your support makes these videos  available to everyone, so thanks [♪ OUTRO]