Autofocusing reading glasses of the future | Nitish Padmanaban

Transcriber: Leslie Gauthier Reviewer: Joanna Pietrulewicz

翻译人员: Pui-Ching Siu 校对人员: Yolanda Zhang

Every single one of us will lose

我们每个人都将会失去，

or has already lost something we rely on every single day.

或者已经失去我们每天依赖的事物。

I am of course talking about our keys.

当然，我是指我们的钥匙。

(Laughter)

（笑声）

Just kidding.

说笑的。

其实，我想讨论的是 我们最重要的感官：视力。

What I actually want to talk about is one of our most important senses: vision.

每天，我们的眼睛都会失去一点点

Every single day we each lose a little bit of our ability

to refocus our eyes

对焦的能力，

until we can't refocus at all.

直到我们完全无法对焦。

We call this condition presbyopia,

我们把这个症状称为老花，

and it affects two billion people worldwide.

它影响着全球二十亿人。

That's right, I said billion.

对的，我说的是亿。

If you haven't heard of presbyopia,

如果你从未听过老花，

and you're wondering, "Where are these two billion people?"

而且很疑惑，“这二十亿人在哪？”

在我开始详细介绍之前， 先简单解释一下。

here's a hint before I get into the details.

老花是人们使用老花镜 或双焦镜的原因。

It's the reason why people wear reading glasses or bifocal lenses.

I'll get started by describing the loss in refocusing ability

首先我会讲解失去对焦能力

leading up to presbyopia.

是怎么导致老花的。

As a newborn, you would have been able to focus

在新生儿时期，你的眼睛具有

接近 6.5 公分的对焦能力，

as close as six and a half centimeters,

if you wished to.

这是最好的情况。

By your mid-20s, you have about half of that focusing power left.

在二十多岁的时候， 你只剩下一半的对焦能力。

10 centimeters or so,

剩下大概 10 公分，

but close enough that you never notice the difference.

但是你不会发现 跟之前有什么差别。

By your late 40s though,

当你四十多岁的时候，

你最多只能对焦大概 25 公分，

the closest you can focus is about 25 centimeters,

甚至更远。

maybe even farther.

在那之后，失去的对焦能力

Losses in focusing ability beyond this point

会开始影响近距离的活动，例如阅读。

start affecting near-vision tasks like reading,

当你 60 岁时，

and by the time you reach age 60,

nothing within a meter radius of you is clear.

半径一米范围内的目标 都会变得模糊不清。

Right now some of you are probably thinking,

现在，在座有人也许在想，

that sounds bad but he means you in a figurative sense,

虽然那听起来很糟糕， 但“你”这个词只是代指

only for the people that actually end up with presbyopia.

那些真正患上老花的人们。

But no, when I say you, I literally mean that every single one of you

不是的，当我说“你”的时候， 我确实是指你们每一个人，

will someday be presbyopic if you aren't already.

如果没准备好， 总有一天会患上老花。

That sounds a bit troubling.

听起来很令人不安。

I want to remind you that presbyopia has been with us for all of human history

我想提醒各位的是， 老花贯穿了人类的历史，

and we've done a lot of different things to try and fix it.

我们尝试过不同的方法来解决它。

So to start, let's imagine that you're sitting at a desk, reading.

首先，想象自己正坐在桌旁读报纸。

If you were presbyopic,

如果你有老花，

it might look a little something like this.

眼前就会是这样一番景象。

任何附近的目标， 例如杂志，会很模糊。

Anything close by, like the magazine, will be blurry.

Moving on to solutions.

不过我们有解决方法。

First, reading glasses.

一、老花镜。

These have lenses with a single focal power

它的镜片调整了单一聚焦力，

tuned so that near objects come into focus.

让你可以对焦附近的目标，

But far objects necessarily go out of focus,

但是对于较远的目标则无法对焦，

meaning you have to constantly switch back and forth

这意味着你需要一直在 戴眼镜和不戴眼镜之间

between wearing and not wearing them.

不停切换。

To solve this problem

为了解决这个问题，

Benjamin Franklin invented what he called "double spectacles."

本杰明·富兰克林 发明了“双重眼镜”，

Today we call those bifocals,

也就是现在的双焦镜。

and what they let him do was see far when he looked up

双焦镜可以帮助他透过 镜片的上半部分看清远处，

and see near when he looked down.

透过镜片的下半部分看清近处。

Today we also have progressive lenses which get rid of the line

今天，我们还有渐进镜片，

可以把那条分隔线去掉， 让聚焦力平滑地上下渐变。

by smoothly varying the focal power from top to bottom.

这些镜片的缺点是，

The downside to both of these

is that you lose field of vision at any given distance,

无论在哪个距离， 你都会失去一部分视野，

because it gets split up from top to bottom like this.

因为聚焦范围是上下分开的。

To see why that's a problem,

为什么这依然是一个问题呢？

想象你正在沿着梯子或楼梯向下走。

imagine that you're climbing down a ladder or stairs.

You look down to get your footing but it's blurry.

你向下看，发现落脚点是模糊的。

Why would it be blurry?

为什么呢？

Well, you look down and that's the near part of the lens,

因为你向下看时透过的是 镜片用来看近处的部分，

but the next step was past arm's reach,

但是你的下一步并非伸手可及，

which for your eyes counts as far.

所以你的眼睛 把它当成了远处的景象。

The next solution I want to point out is a little less common

下一个解决方法相对少见，

但比较常见于隐形眼镜或激光手术，

but comes up in contact lenses or LASIK surgeries,

and it's called monovision.

它叫单眼视。

它把主眼用来对焦远处，

It works by setting up the dominant eye to focus far

and the other eye to focus near.

另一只眼对焦近处。

Your brain does the work of intelligently putting together

你的大脑可以聪明地把每只眼

最清晰的视觉部分结合在一起。

the sharpest parts from each eye's view,

但是，因为两只眼睛 看见的事物略有不同，

but the two eyes see slightly different things,

所以用双眼判断距离会比较困难。

and that makes it harder to judge distances binocularly.

So where does that leave us?

那么，下一步怎么办呢？

We've come up with a lot of solutions

我们已经找到了许多解决方案，

但是它们都不会帮助 恢复自然的视力。

but none of them quite restore natural refocusing.

None of them let you just look at something

它们没办法让你 在观察任何事物时

and expect it to be in focus.

都能准确对焦。

But why?

这是为什么呢？

Well, to explain that

在解释这个问题之前，

we'll want to take a look at the anatomy of the human eye.

我们需要简单了解一下 人类眼睛的结构。

The part of the eye that allows us to refocus to different distances

眼睛的晶状体让我们能够

在不同距离上对焦。

is called the crystalline lens.

There are muscles surrounding the lens that can deform it into different shapes,

晶状体附近的肌肉 可以通过改变它的形状，

which in turn changes its focusing power.

来改变它的聚焦能力。

What happens when someone becomes presbyopic?

人类患上老花时会怎么样？

It turns out that the crystalline lens stiffens

晶状体会硬化，

to the point that it doesn't really change shape anymore.

导致无法再改变形状。

现在，回想我之前 列出的解决方案，

Now, thinking back on all the solutions I listed earlier,

we can see that they all have something in common with the others

它们都有共同之处，

but not with our eyes,

但是都和我们眼睛的构造不同，

and that is that they're all static.

因为它们都是静止的，

It's like the optical equivalent of a pirate with a peg leg.

就像是装了义腿的海盗。

那什么是视觉中的义腿呢？

What is the optical equivalent of a modern prosthetic leg?

The last several decades have seen the creation and rapid development

过去几十年间，

“焦距可调镜片”技术 获得了急速发展。

of what are called "focus-tunable lenses."

There are several different types.

这种镜片有不同的种类。

机械调节阿尔瓦雷斯镜片、

Mechanically-shifted Alvarez lenses,

deformable liquid lenses

可变形液态镜片

and electronically-switched, liquid crystal lenses.

和电子开关液晶镜片。

Now these have their own trade-offs,

它们都有自身的优点和局限性，

but what they don't skimp on is the visual experience.

但是都能够提供 充足的视觉体验——

完整的视野， 在任何距离范围内都很清晰。

Full-field-of-view vision that can be sharp at any desired distance.

OK, great. The lenses we need already exist.

很棒，我们已经有这些镜片了。

Problem solved, right?

问题解决了，对吗？

Not so fast.

没这么快。

Focus-tunable lenses add a bit of complexity to the equation.

焦距可调镜片增加了自身的复杂性。

The lenses don't have any way of knowing what distance they should be focused to.

这些镜片无法得知 应该对焦于哪个距离。

我们的眼镜需要做到，

What we need are glasses

that, when you're looking far, far objects are sharp,

当你看远处，远的目标清晰，

and when you look near,

当你看近处，

near objects come into focus in your field of view,

近处的目标能够准确对焦，

without you having to think about it.

你甚至完全不会意识到这种转换。

What I've worked on these last few years at Stanford

过去几年中，我一直在斯坦福

is building that exact intelligence around the lenses.

从事这种智能镜片相关的研究。

Our prototype borrows technology from virtual and augmented reality systems

我们的原型利用了 虚拟现实和增强现实技术

to estimate focusing distance.

来预测对焦的距离。

We have an eye tracker that can tell what direction our eyes are focused in.

这种装置内部有一个 可以追踪眼睛对焦方向的追踪器。

使用这两种技术， 我们可以把你的注视点三角化，

Using two of these, we can triangulate your gaze direction

to get a focus estimate.

从而预测对焦。

Just in case though, to increase reliability,

以防万一，为了增加可靠性，

我们也增加了距离传感器。

we also added a distance sensor.

这是一个相机，看向外侧，

The sensor is a camera that looks out at the world

并汇报与目标之间的距离。

and reports distances to objects.

We can again use your gaze direction to get a distance estimate

然后，我们可以使用你的注视点

for a second time.

再次预测距离。

We then fuse those two distance estimates

接着，我们会融合 这两个距离预测数据，

and update the focus-tunable lens power accordingly.

对焦距可调镜片 进行相应的调整更新。

The next step for us was to test our device on actual people.

下一步，我们需要 让人们测试装置。

So we recruited about 100 presbyopes and had them test our device

我们找来了大约 100 名老花患者， 让他们测试我们的装置，

while we measured their performance.

然后测量他们的表现。

What we saw convinced us right then that autofocals were the future.

结果使我们 对自动聚焦镜的前景信心倍增。

Our participants could see more clearly, they could focus more quickly

参与者可以看得更清楚、对焦更快，

他们认为比起目前的矫正方法，

and they thought it was an easier and better focusing experience

我们的装置能够更准确、 更容易的对焦，

than their current correction.

简单来说，对于视力，

To put it simply, when it comes to vision,

相比当今的静止矫正方法， 自动聚焦镜不需要牺牲任何功能。

autofocals don't compromise like static corrections in use today do.

But I don't want to get ahead of myself.

但我不想过于激进。

There's a lot of work for my colleagues and me left to do.

我和同事还需要处理许多事项。

For example, our glasses are a bit --

比如说，我们的眼镜有点——

(Laughter)

（笑声）

bulky, maybe?

——笨重，也许吧？

And one reason for this is that we used bulkier components

一个原因就是，我们使用了 研究和工业领域比较常用的

that are often intended for research use or industrial use.

更笨重的零件。

Another is that we need to strap everything down

另外，我们还需要 把全部部件整合在一起，

because current eye-tracking algorithms don't have the robustness that we need.

因为目前的目光测量算法 远不如我们预想的稳定。

So moving forward,

所以，下一步，

as we move from a research setting into a start-up,

当我们把这项技术 从研究项目转变成初创公司时，

we plan to make future autofocals

我们打算把将来的自动对焦镜

eventually look a little bit more like normal glasses.

做得更像正常的眼镜。

For this to happen, we'll need to significantly improve

为了达到这个目的， 我们需要在更大程度上改进

the robustness of our eye-tracking solution.

目光测量算法的稳定性。

We'll also need to incorporate smaller and more efficient electronics and lenses.

我们也需要加入更小、 更高效的电子零件和镜片。

That said, even with our current prototype,

也就是说， 即使处在原型阶段，

we've shown that today's focus-tunable lens technology

当前的焦距可调镜片科技

is capable of outperforming traditional forms of static correction.

也比传统静止矫正工具更加出色，

So it's only a matter of time.

一切只是时间问题。

It's pretty clear that in the near future,

很明显，在将来，

我们可以专注于更重要的东西，

instead of worrying about which pair of glasses to use and when,

而不再需要纠结 什么时候用什么眼镜。

we'll be able to just focus on the important things.

Thank you.

谢谢。

(Applause)

（掌声）