The major problems are refractive errors like myopia and astigmatism.

要问题是近视和散光等屈光不正。

Now, when light enters glass, it's a different refractive index, so it actually bends the light.

现在，当光线进入玻璃时，因为它折射率不，所以它实际上会弯曲光线。

Key features This refractive error has three key features: Image is formed behind the retina.

关键特征这种屈光不正有三个要特征：图像在视网膜后面形成。

This substance has a high refractive index, meaning the speed of light passing through it is greatly reduced.

这种物质折射率很高，意味着光穿过它速度会大幅降低。

To combat this rain visibility problem, 3M actually developed these elements, which are retroreflectors that have different refractive indices.

为了解决雨天能见度问题，3M 公司实际上开发了这些元件，它是具有不折射率逆反射器。

This is also the reason why we use cycloplegic or muscle paralyzing drops before estimating the amount of refractive error.

这也是我在测量屈光不正之前使用睫状肌麻痹或肌肉麻痹药水原因。

And on this side, we have elements that have a 2.4 refractive index and work better in wet conditions.

而在另一侧，我有折射率为 2.4 元素，它在潮湿条件下表现更好。

Glasses and contact lenses bend light to compensate for these refractive errors.

镜和隐形镜会弯曲光线以补偿这些屈光不正。

But many people develop refractive errors, either during childhood as their eyes are growing, or in later life as their eyes age.

但是很多人产生了屈光不正。或是发生在孩童时期当他睛成长时，或是在后期当他睛变老时候。

It's even possible to correct vision with surgery using lasers that change the shape of the cornea and alter its refractive properties.

甚至可以通过外科手术来矫正视力通过激光来改变角膜形状和改变它折光特性。

So on this side, we have elements that have a refractive index of 1.9, and they work well in dry conditions.

在这一侧，我有折射率为 1.9 元素，它在干燥条件下表现良好。

Keratomileusis corrects what are called refractive errors: imperfections in the way the eye focuses incoming light.

角膜磨镶术可以纠正所谓屈光不正：睛聚焦入射光方式存在缺陷。

People with refractive errors can still see color, movement, and light, but the details of what they're looking at are out of focus.

有屈光不正人仍然能够看到颜色，移动，和光，但是他正在看细节是模糊不清。

Diagnosis Retinoscopy: a hand-held device that throws light in the eye and allowing us to observe its movements and reflection, hence helping to confirm the refractive error.

一种手持设备，向睛投射光线，观察睛运动和反射，从而帮助确认屈光不正。

So where the retroreflectors act ideally under dry conditions, as soon as water is on top of them, their refractive index is lowered by a ratio of 1.33.

因此，当反射器在干燥条件下理想工作时，一旦水覆盖在其上，它折射率就会降低到 1.33 比例。

Some have the regular glass beads on them, and other ones have the 3M elements on them with the 1.9 refractive index or the 2.4 refractive index or a combination of those.

有上面有普通玻璃珠，有上面有折射率为 1.9 或 2.4 3M 元件，或者是它组合。

" A common misunderstanding is that a surgery can cure myopia, but in fact, the procedure can only remove the need for glasses, or apply the refractive function of glasses to the eyeball, " he said.

“目前最常见误区是很多人都认为手术可以治愈近视，实际上严格来讲，手术仅仅是‘摘镜’，也就是说，通过手术手段，把镜屈光度施加到球上，让我球能够匹配过度生长度数。

" In addition, refractive index can also be used to 'invisibility', for example, objects with high borosilicate glass materials can also be 'invisible' when moving in glycerol with a refractive index close to its own, " Chu noted.

“此外，折射率也可以用来‘隐形’，比如高硼硅玻璃材料物体在折射率接近自身甘油中运动时也可以‘隐形’，”褚指出。

Zhang Qingsong, director of the refractive surgery center at the Wuhan Aier Eye Hospital in Wuhan, Hubei province, said it carried out around 2,000 refractive operations a month in June and July, double the monthly number earlier in the year.

湖北武汉爱尔科医院屈光专科任张青松表示，每年6至7月，医院都要实施近2000台近视手术，是今年其他月份每月手术量两倍。

This is actually one of the principles of realizing the " invisible cloak" , when the fabric of a garment and the air refractive index are the same, people can be freely " invisible" after wearing it, said the expert.

这位专家说，，这其实也是实现 “隐形斗篷”原理之一，当一件衣服面料与空气折射率相时，人穿上后就可以自由 " 隐形" 。