The major problems are refractive errors like myopia and astigmatism.

主要问题是近视和散光等屈光不正。

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主要特征：图像在视网膜后面形成。

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

这也是我们在测量屈光不正之前使用睫状肌麻痹或肌肉麻痹眼药水的原因。

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们眼睛成长时，或是在后期当他们的眼睛变老的时候。

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

眼镜和隐形眼镜会弯曲光线以补偿这些屈光不正。

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

有屈光不正的人仍然能够看到颜色，移动，和光，但是他们正在的看的细节是模糊不清的。

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的屈光不正：眼睛聚焦入射光的方式存在缺陷。

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，向眼睛投射光线，观察眼睛的运动和反射，从而帮助确认屈光不正。