[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.88,0:00:02.81,Default,,0000,0000,0000,,Every single one of us will lose
Dialogue: 0,0:00:02.83,0:00:06.68,Default,,0000,0000,0000,,or has already lost something\Nwe rely on every single day.
Dialogue: 0,0:00:06.71,0:00:09.52,Default,,0000,0000,0000,,I am of course talking about our keys.
Dialogue: 0,0:00:09.54,0:00:11.18,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:00:11.21,0:00:12.48,Default,,0000,0000,0000,,Just kidding.
Dialogue: 0,0:00:12.50,0:00:16.31,Default,,0000,0000,0000,,What I actually want to talk about is one\Nof our most important senses: vision.
Dialogue: 0,0:00:16.33,0:00:19.14,Default,,0000,0000,0000,,Every single day we each lose\Na little bit of our ability
Dialogue: 0,0:00:19.17,0:00:20.48,Default,,0000,0000,0000,,to refocus our eyes
Dialogue: 0,0:00:20.50,0:00:22.81,Default,,0000,0000,0000,,until we can't refocus at all.
Dialogue: 0,0:00:22.83,0:00:24.81,Default,,0000,0000,0000,,We call this condition presbyopia,
Dialogue: 0,0:00:24.83,0:00:27.35,Default,,0000,0000,0000,,and it affects two billion\Npeople worldwide.
Dialogue: 0,0:00:27.38,0:00:29.52,Default,,0000,0000,0000,,That's right, I said billion.
Dialogue: 0,0:00:29.54,0:00:31.27,Default,,0000,0000,0000,,If you haven't heard of presbyopia,
Dialogue: 0,0:00:31.29,0:00:34.10,Default,,0000,0000,0000,,and you're wondering,\N"Where are these two billion people?"
Dialogue: 0,0:00:34.12,0:00:36.23,Default,,0000,0000,0000,,here's a hint before\NI get into the details.
Dialogue: 0,0:00:36.25,0:00:39.52,Default,,0000,0000,0000,,It's the reason why people wear\Nreading glasses or bifocal lenses.
Dialogue: 0,0:00:39.54,0:00:42.40,Default,,0000,0000,0000,,I'll get started by describing\Nthe loss in refocusing ability
Dialogue: 0,0:00:42.42,0:00:43.93,Default,,0000,0000,0000,,leading up to presbyopia.
Dialogue: 0,0:00:43.96,0:00:46.18,Default,,0000,0000,0000,,As a newborn, you would have\Nbeen able to focus
Dialogue: 0,0:00:46.21,0:00:48.35,Default,,0000,0000,0000,,as close as six and a half centimeters,
Dialogue: 0,0:00:48.38,0:00:49.64,Default,,0000,0000,0000,,if you wished to.
Dialogue: 0,0:00:49.67,0:00:52.81,Default,,0000,0000,0000,,By your mid-20s, you have about\Nhalf of that focusing power left.
Dialogue: 0,0:00:52.83,0:00:54.10,Default,,0000,0000,0000,,10 centimeters or so,
Dialogue: 0,0:00:54.12,0:00:56.68,Default,,0000,0000,0000,,but close enough that you never\Nnotice the difference.
Dialogue: 0,0:00:56.71,0:00:57.98,Default,,0000,0000,0000,,By your late 40s though,
Dialogue: 0,0:00:58.00,0:01:00.35,Default,,0000,0000,0000,,the closest you can focus\Nis about 25 centimeters,
Dialogue: 0,0:01:00.38,0:01:01.64,Default,,0000,0000,0000,,maybe even farther.
Dialogue: 0,0:01:01.67,0:01:03.77,Default,,0000,0000,0000,,Losses in focusing ability\Nbeyond this point
Dialogue: 0,0:01:03.79,0:01:06.02,Default,,0000,0000,0000,,start affecting near-vision\Ntasks like reading,
Dialogue: 0,0:01:06.04,0:01:07.64,Default,,0000,0000,0000,,and by the time you reach age 60,
Dialogue: 0,0:01:07.67,0:01:10.02,Default,,0000,0000,0000,,nothing within a meter\Nradius of you is clear.
Dialogue: 0,0:01:10.04,0:01:12.31,Default,,0000,0000,0000,,Right now some of you\Nare probably thinking,
Dialogue: 0,0:01:12.33,0:01:15.64,Default,,0000,0000,0000,,that sounds bad but he means\Nyou in a figurative sense,
Dialogue: 0,0:01:15.67,0:01:19.10,Default,,0000,0000,0000,,only for the people that actually\Nend up with presbyopia.
Dialogue: 0,0:01:19.12,0:01:23.56,Default,,0000,0000,0000,,But no, when I say you, I literally mean\Nthat every single one of you
Dialogue: 0,0:01:23.58,0:01:26.81,Default,,0000,0000,0000,,will someday be presbyopic\Nif you aren't already.
Dialogue: 0,0:01:26.83,0:01:28.23,Default,,0000,0000,0000,,That sounds a bit troubling.
Dialogue: 0,0:01:28.25,0:01:31.93,Default,,0000,0000,0000,,I want to remind you that presbyopia\Nhas been with us for all of human history
Dialogue: 0,0:01:31.96,0:01:34.77,Default,,0000,0000,0000,,and we've done a lot\Nof different things to try and fix it.
Dialogue: 0,0:01:34.79,0:01:38.68,Default,,0000,0000,0000,,So to start, let's imagine\Nthat you're sitting at a desk, reading.
Dialogue: 0,0:01:38.71,0:01:40.06,Default,,0000,0000,0000,,If you were presbyopic,
Dialogue: 0,0:01:40.08,0:01:42.14,Default,,0000,0000,0000,,it might look a little\Nsomething like this.
Dialogue: 0,0:01:42.17,0:01:45.06,Default,,0000,0000,0000,,Anything close by,\Nlike the magazine, will be blurry.
Dialogue: 0,0:01:45.08,0:01:46.43,Default,,0000,0000,0000,,Moving on to solutions.
Dialogue: 0,0:01:46.46,0:01:48.10,Default,,0000,0000,0000,,First, reading glasses.
Dialogue: 0,0:01:48.12,0:01:50.18,Default,,0000,0000,0000,,These have lenses\Nwith a single focal power
Dialogue: 0,0:01:50.21,0:01:52.60,Default,,0000,0000,0000,,tuned so that near objects\Ncome into focus.
Dialogue: 0,0:01:52.62,0:01:55.23,Default,,0000,0000,0000,,But far objects\Nnecessarily go out of focus,
Dialogue: 0,0:01:55.25,0:01:57.73,Default,,0000,0000,0000,,meaning you have to constantly\Nswitch back and forth
Dialogue: 0,0:01:57.75,0:01:59.52,Default,,0000,0000,0000,,between wearing and not wearing them.
Dialogue: 0,0:01:59.54,0:02:00.81,Default,,0000,0000,0000,,To solve this problem
Dialogue: 0,0:02:00.83,0:02:04.10,Default,,0000,0000,0000,,Benjamin Franklin invented\Nwhat he called "double spectacles."
Dialogue: 0,0:02:04.12,0:02:06.23,Default,,0000,0000,0000,,Today we call those bifocals,
Dialogue: 0,0:02:06.25,0:02:09.68,Default,,0000,0000,0000,,and what they let him do\Nwas see far when he looked up
Dialogue: 0,0:02:09.71,0:02:11.43,Default,,0000,0000,0000,,and see near when he looked down.
Dialogue: 0,0:02:11.46,0:02:14.43,Default,,0000,0000,0000,,Today we also have progressive lenses\Nwhich get rid of the line
Dialogue: 0,0:02:14.46,0:02:17.06,Default,,0000,0000,0000,,by smoothly varying the focal power\Nfrom top to bottom.
Dialogue: 0,0:02:17.08,0:02:18.52,Default,,0000,0000,0000,,The downside to both of these
Dialogue: 0,0:02:18.54,0:02:21.14,Default,,0000,0000,0000,,is that you lose field of vision\Nat any given distance,
Dialogue: 0,0:02:21.17,0:02:23.77,Default,,0000,0000,0000,,because it gets split up\Nfrom top to bottom like this.
Dialogue: 0,0:02:23.79,0:02:25.18,Default,,0000,0000,0000,,To see why that's a problem,
Dialogue: 0,0:02:25.21,0:02:28.06,Default,,0000,0000,0000,,imagine that you're climbing\Ndown a ladder or stairs.
Dialogue: 0,0:02:28.08,0:02:31.68,Default,,0000,0000,0000,,You look down to get\Nyour footing but it's blurry.
Dialogue: 0,0:02:31.71,0:02:33.10,Default,,0000,0000,0000,,Why would it be blurry?
Dialogue: 0,0:02:33.12,0:02:36.56,Default,,0000,0000,0000,,Well, you look down\Nand that's the near part of the lens,
Dialogue: 0,0:02:36.58,0:02:39.14,Default,,0000,0000,0000,,but the next step was past arm's reach,
Dialogue: 0,0:02:39.17,0:02:41.27,Default,,0000,0000,0000,,which for your eyes counts as far.
Dialogue: 0,0:02:41.29,0:02:44.18,Default,,0000,0000,0000,,The next solution I want to point out\Nis a little less common
Dialogue: 0,0:02:44.21,0:02:46.60,Default,,0000,0000,0000,,but comes up in contact lenses\Nor LASIK surgeries,
Dialogue: 0,0:02:46.62,0:02:47.98,Default,,0000,0000,0000,,and it's called monovision.
Dialogue: 0,0:02:48.00,0:02:50.52,Default,,0000,0000,0000,,It works by setting up\Nthe dominant eye to focus far
Dialogue: 0,0:02:50.54,0:02:52.14,Default,,0000,0000,0000,,and the other eye to focus near.
Dialogue: 0,0:02:52.17,0:02:54.98,Default,,0000,0000,0000,,Your brain does the work\Nof intelligently putting together
Dialogue: 0,0:02:55.00,0:02:56.98,Default,,0000,0000,0000,,the sharpest parts from each eye's view,
Dialogue: 0,0:02:57.00,0:02:59.27,Default,,0000,0000,0000,,but the two eyes see\Nslightly different things,
Dialogue: 0,0:02:59.29,0:03:01.93,Default,,0000,0000,0000,,and that makes it harder\Nto judge distances binocularly.
Dialogue: 0,0:03:01.96,0:03:03.35,Default,,0000,0000,0000,,So where does that leave us?
Dialogue: 0,0:03:03.38,0:03:05.23,Default,,0000,0000,0000,,We've come up with a lot of solutions
Dialogue: 0,0:03:05.25,0:03:07.85,Default,,0000,0000,0000,,but none of them quite restore\Nnatural refocusing.
Dialogue: 0,0:03:07.88,0:03:09.93,Default,,0000,0000,0000,,None of them let you\Njust look at something
Dialogue: 0,0:03:09.96,0:03:11.43,Default,,0000,0000,0000,,and expect it to be in focus.
Dialogue: 0,0:03:11.46,0:03:12.81,Default,,0000,0000,0000,,But why?
Dialogue: 0,0:03:12.83,0:03:14.10,Default,,0000,0000,0000,,Well, to explain that
Dialogue: 0,0:03:14.12,0:03:16.85,Default,,0000,0000,0000,,we'll want to take a look\Nat the anatomy of the human eye.
Dialogue: 0,0:03:16.88,0:03:20.10,Default,,0000,0000,0000,,The part of the eye that allows us\Nto refocus to different distances
Dialogue: 0,0:03:20.12,0:03:21.68,Default,,0000,0000,0000,,is called the crystalline lens.
Dialogue: 0,0:03:21.71,0:03:25.56,Default,,0000,0000,0000,,There are muscles surrounding the lens\Nthat can deform it into different shapes,
Dialogue: 0,0:03:25.58,0:03:27.68,Default,,0000,0000,0000,,which in turn changes its focusing power.
Dialogue: 0,0:03:27.71,0:03:30.18,Default,,0000,0000,0000,,What happens when someone\Nbecomes presbyopic?
Dialogue: 0,0:03:30.21,0:03:32.43,Default,,0000,0000,0000,,It turns out that\Nthe crystalline lens stiffens
Dialogue: 0,0:03:32.46,0:03:35.14,Default,,0000,0000,0000,,to the point that it doesn't\Nreally change shape anymore.
Dialogue: 0,0:03:35.17,0:03:38.89,Default,,0000,0000,0000,,Now, thinking back\Non all the solutions I listed earlier,
Dialogue: 0,0:03:38.92,0:03:42.64,Default,,0000,0000,0000,,we can see that they all have\Nsomething in common with the others
Dialogue: 0,0:03:42.67,0:03:44.14,Default,,0000,0000,0000,,but not with our eyes,
Dialogue: 0,0:03:44.17,0:03:46.18,Default,,0000,0000,0000,,and that is that they're all static.
Dialogue: 0,0:03:46.21,0:03:49.10,Default,,0000,0000,0000,,It's like the optical equivalent\Nof a pirate with a peg leg.
Dialogue: 0,0:03:49.12,0:03:52.27,Default,,0000,0000,0000,,What is the optical equivalent\Nof a modern prosthetic leg?
Dialogue: 0,0:03:52.29,0:03:55.56,Default,,0000,0000,0000,,The last several decades have seen\Nthe creation and rapid development
Dialogue: 0,0:03:55.58,0:03:58.27,Default,,0000,0000,0000,,of what are called "focus-tunable lenses."
Dialogue: 0,0:03:58.29,0:03:59.98,Default,,0000,0000,0000,,There are several different types.
Dialogue: 0,0:04:00.00,0:04:01.81,Default,,0000,0000,0000,,Mechanically-shifted Alvarez lenses,
Dialogue: 0,0:04:01.83,0:04:03.27,Default,,0000,0000,0000,,deformable liquid lenses
Dialogue: 0,0:04:03.29,0:04:05.85,Default,,0000,0000,0000,,and electronically-switched,\Nliquid crystal lenses.
Dialogue: 0,0:04:05.88,0:04:07.68,Default,,0000,0000,0000,,Now these have their own trade-offs,
Dialogue: 0,0:04:07.71,0:04:10.31,Default,,0000,0000,0000,,but what they don't skimp on\Nis the visual experience.
Dialogue: 0,0:04:10.33,0:04:13.60,Default,,0000,0000,0000,,Full-field-of-view vision that can be\Nsharp at any desired distance.
Dialogue: 0,0:04:13.62,0:04:15.77,Default,,0000,0000,0000,,OK, great. The lenses we need\Nalready exist.
Dialogue: 0,0:04:15.79,0:04:17.68,Default,,0000,0000,0000,,Problem solved, right?
Dialogue: 0,0:04:17.71,0:04:19.14,Default,,0000,0000,0000,,Not so fast.
Dialogue: 0,0:04:19.17,0:04:22.14,Default,,0000,0000,0000,,Focus-tunable lenses add a bit\Nof complexity to the equation.
Dialogue: 0,0:04:22.17,0:04:26.02,Default,,0000,0000,0000,,The lenses don't have any way of knowing\Nwhat distance they should be focused to.
Dialogue: 0,0:04:26.04,0:04:27.35,Default,,0000,0000,0000,,What we need are glasses
Dialogue: 0,0:04:27.38,0:04:29.93,Default,,0000,0000,0000,,that, when you're looking far,\Nfar objects are sharp,
Dialogue: 0,0:04:29.96,0:04:31.27,Default,,0000,0000,0000,,and when you look near,
Dialogue: 0,0:04:31.29,0:04:33.73,Default,,0000,0000,0000,,near objects come into focus\Nin your field of view,
Dialogue: 0,0:04:33.75,0:04:35.60,Default,,0000,0000,0000,,without you having to think about it.
Dialogue: 0,0:04:35.62,0:04:38.14,Default,,0000,0000,0000,,What I've worked on\Nthese last few years at Stanford
Dialogue: 0,0:04:38.17,0:04:40.77,Default,,0000,0000,0000,,is building that exact intelligence\Naround the lenses.
Dialogue: 0,0:04:40.79,0:04:44.39,Default,,0000,0000,0000,,Our prototype borrows technology\Nfrom virtual and augmented reality systems
Dialogue: 0,0:04:44.42,0:04:45.93,Default,,0000,0000,0000,,to estimate focusing distance.
Dialogue: 0,0:04:45.96,0:04:49.60,Default,,0000,0000,0000,,We have an eye tracker that can tell\Nwhat direction our eyes are focused in.
Dialogue: 0,0:04:49.62,0:04:52.43,Default,,0000,0000,0000,,Using two of these, we can\Ntriangulate your gaze direction
Dialogue: 0,0:04:52.46,0:04:53.77,Default,,0000,0000,0000,,to get a focus estimate.
Dialogue: 0,0:04:53.79,0:04:55.98,Default,,0000,0000,0000,,Just in case though,\Nto increase reliability,
Dialogue: 0,0:04:56.00,0:04:57.56,Default,,0000,0000,0000,,we also added a distance sensor.
Dialogue: 0,0:04:57.58,0:04:59.98,Default,,0000,0000,0000,,The sensor is a camera\Nthat looks out at the world
Dialogue: 0,0:05:00.00,0:05:01.60,Default,,0000,0000,0000,,and reports distances to objects.
Dialogue: 0,0:05:01.62,0:05:04.60,Default,,0000,0000,0000,,We can again use your gaze direction\Nto get a distance estimate
Dialogue: 0,0:05:04.62,0:05:05.89,Default,,0000,0000,0000,,for a second time.
Dialogue: 0,0:05:05.92,0:05:07.89,Default,,0000,0000,0000,,We then fuse those two distance estimates
Dialogue: 0,0:05:07.92,0:05:10.39,Default,,0000,0000,0000,,and update the focus-tunable\Nlens power accordingly.
Dialogue: 0,0:05:10.42,0:05:13.35,Default,,0000,0000,0000,,The next step for us was\Nto test our device on actual people.
Dialogue: 0,0:05:13.38,0:05:16.52,Default,,0000,0000,0000,,So we recruited about 100 presbyopes\Nand had them test our device
Dialogue: 0,0:05:16.54,0:05:18.35,Default,,0000,0000,0000,,while we measured their performance.
Dialogue: 0,0:05:18.38,0:05:21.64,Default,,0000,0000,0000,,What we saw convinced us right then\Nthat autofocals were the future.
Dialogue: 0,0:05:21.67,0:05:25.02,Default,,0000,0000,0000,,Our participants could see more clearly,\Nthey could focus more quickly
Dialogue: 0,0:05:25.04,0:05:28.06,Default,,0000,0000,0000,,and they thought it was an easier\Nand better focusing experience
Dialogue: 0,0:05:28.08,0:05:29.56,Default,,0000,0000,0000,,than their current correction.
Dialogue: 0,0:05:29.58,0:05:31.64,Default,,0000,0000,0000,,To put it simply, when it comes to vision,
Dialogue: 0,0:05:31.67,0:05:34.89,Default,,0000,0000,0000,,autofocals don't compromise\Nlike static corrections in use today do.
Dialogue: 0,0:05:34.92,0:05:36.85,Default,,0000,0000,0000,,But I don't want to get ahead of myself.
Dialogue: 0,0:05:36.88,0:05:39.60,Default,,0000,0000,0000,,There's a lot of work\Nfor my colleagues and me left to do.
Dialogue: 0,0:05:39.62,0:05:41.89,Default,,0000,0000,0000,,For example, our glasses are a bit --
Dialogue: 0,0:05:41.92,0:05:42.93,Default,,0000,0000,0000,,(Laughter)
Dialogue: 0,0:05:42.96,0:05:44.31,Default,,0000,0000,0000,,bulky, maybe?
Dialogue: 0,0:05:44.33,0:05:47.68,Default,,0000,0000,0000,,And one reason for this\Nis that we used bulkier components
Dialogue: 0,0:05:47.71,0:05:50.52,Default,,0000,0000,0000,,that are often intended\Nfor research use or industrial use.
Dialogue: 0,0:05:50.54,0:05:52.81,Default,,0000,0000,0000,,Another is that we need\Nto strap everything down
Dialogue: 0,0:05:52.83,0:05:56.64,Default,,0000,0000,0000,,because current eye-tracking algorithms\Ndon't have the robustness that we need.
Dialogue: 0,0:05:56.67,0:05:57.98,Default,,0000,0000,0000,,So moving forward,
Dialogue: 0,0:05:58.00,0:06:00.48,Default,,0000,0000,0000,,as we move from a research\Nsetting into a start-up,
Dialogue: 0,0:06:00.50,0:06:02.43,Default,,0000,0000,0000,,we plan to make future autofocals
Dialogue: 0,0:06:02.46,0:06:05.02,Default,,0000,0000,0000,,eventually look a little bit more\Nlike normal glasses.
Dialogue: 0,0:06:05.04,0:06:08.39,Default,,0000,0000,0000,,For this to happen,\Nwe'll need to significantly improve
Dialogue: 0,0:06:08.42,0:06:10.56,Default,,0000,0000,0000,,the robustness\Nof our eye-tracking solution.
Dialogue: 0,0:06:10.58,0:06:14.77,Default,,0000,0000,0000,,We'll also need to incorporate smaller\Nand more efficient electronics and lenses.
Dialogue: 0,0:06:14.79,0:06:16.98,Default,,0000,0000,0000,,That said, even with\Nour current prototype,
Dialogue: 0,0:06:17.00,0:06:19.73,Default,,0000,0000,0000,,we've shown that today's\Nfocus-tunable lens technology
Dialogue: 0,0:06:19.75,0:06:23.31,Default,,0000,0000,0000,,is capable of outperforming\Ntraditional forms of static correction.
Dialogue: 0,0:06:23.33,0:06:24.98,Default,,0000,0000,0000,,So it's only a matter of time.
Dialogue: 0,0:06:25.00,0:06:27.06,Default,,0000,0000,0000,,It's pretty clear that in the near future,
Dialogue: 0,0:06:27.08,0:06:30.14,Default,,0000,0000,0000,,instead of worrying about which pair\Nof glasses to use and when,
Dialogue: 0,0:06:30.17,0:06:32.71,Default,,0000,0000,0000,,we'll be able to just focus\Non the important things.
Dialogue: 0,0:06:33.67,0:06:34.93,Default,,0000,0000,0000,,Thank you.
Dialogue: 0,0:06:34.96,0:06:36.58,Default,,0000,0000,0000,,(Applause)