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HYPEROPIA
远视
Anatomy
解剖学
Before we can describe hyperopia, let's compare the eye ball to a camera for better understanding.
在我们描述远视之前，为了更好的理解，我们把眼球比作相机。
When we take a picture, light after reflecting from an object enters the camera and passes through:
当我们拍照时，从物体反射回来的光线进入相机，并通过：
First, a transparent glass in front of the aperture of the camera,
首先，它通过相机光圈前面的透明玻璃。
then secondly, a lens that helps us in focusing light rays,
其次，它通过一个帮助我们聚焦光线的相机镜头，
and lastly, a film on which light is focused for a clear picture.
最后是相机胶片，光线聚集在相机胶片上，以获得清晰的图像。
Eye is somewhat similar.
眼睛有点相似。
As when we see an object, the light after reflection from that object enters our eye through:
我们看到一个物体时，物体反射后的光通过以下途径进入我们的眼睛：
Firstly, cornea: the transparent curved front part of eye,
首先，角膜，角膜是眼睛前面透明的弯曲部分，
then secondly, through the crystalline lens that helps us in focusing the light rays,
然后，它穿过帮助我们聚焦光线的晶体，
and lastly, the retina: light sensitive receptor cells in the posterior part of the eye ball on which light is focused for a clear image.
最后，视网膜，也就是眼球后部的感光细胞，光线聚焦在视网膜上以获得清晰的图像。
Definition of Hyperopia
远视的定义
It is a form of refractive error: inability to refract, bend, focus the light rays properly in which parallel rays of light i.e. coming from a distinct object after entering the eye are focused behind the retina with accommodation (eye muscles) at rest.
远视是屈光不正的一种形式，无法折射、弯曲、聚焦光线，即平行来自一个物体的特定光线，进入眼睛后，聚焦在视网膜后面，而不是眼睛静止时调节眼肌聚焦在视网膜上。
Key features
关键特征
This refractive error has three key features:
这种屈光不正有三个主要特征：
Image is formed behind the retina.
图像在视网膜后面形成。
In normal people, image has to be focused on the retina for it to be clear.
对于正常人来说，图像必须聚焦在视网膜上才能清晰。
Parallel light rays.
平行光线。
The rays that only come from objects at 6 meters or beyond, must be used for assessment.
必须使用来自6米或更远物体的射线进行评估。
As when objects come closer than 6 meters, light rays start to diverge, changing their focus.
当物体接近6米时，光线开始发散，改变焦点。
This is why we place Snellen's chart at 6 meters.
这就是为什么我们把斯内伦视力表放在6米的位置。
Eye must be at rest.
眼睛必须静止。
Just like a DSLR camera's focusing power can be changed by rotating its zoom lens, eye changes its focusing power by changing the shape of its lens with the help of contraction and relaxation of certain muscles located inside the eye ball.
就像数码单反相机可以通过旋转变焦镜头来改变调焦能力一样，眼睛也可以通过改变镜头的形状来改变调焦能力，而这种改变是通过眼球内某些肌肉的收缩和放松来实现的。
These muscles must be at rest to correctly access the eye's focusing power.
这些肌肉必须处于静止状态，才能正确地获得眼睛的聚焦力。
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。
Misnomer
误称
Both hyperopia and myopia have abnormal distant vision, i.e. they cannot focus distant objects clearly.
远视和近视都有不正常的远视，即不能清楚地聚焦远处的物体。
But a unique thing about hyperopia is that if these patients increase the power of their lens by contraction of certain intraocular muscles, they can focus the image accurately on their retina.
但远视的一个独特之处在于，如果这些患者通过收缩某些眼内肌肉来增加晶状体的放大率，他们就可以将图像准确地聚焦到视网膜上。
This will result in excessive and continuous use of intraocular (ciliary) muscles in order to keep the image focused on the retina, resulting in pain.
这将导致过度和持续地使用眼内(睫状肌)，以保持图像聚焦在视网膜上，导致疼痛。
Also, when they try to see near objects, their eyes will require even more focusing power which these muscles can no longer provide hence causing near objects to become blurry.
此外，当他们试图看到近处的物体时，他们的眼睛将需要更多的聚焦能力，而这些肌肉已经无法提供，因此导致附近的物体变得模糊。
So, a lot of hyperopic patients (not all), with less degree of hyperopia, will say that they see distant objects clearly but they have pain/discomfort in their eyes or their eyes get tired and also near vision is mostly not that good.
因此，很多远视患者(并非所有)，远视程度较低的人，会说他们看得很清楚，但眼睛有疼痛/不适，或眼睛感到疲倦，近处的物体看起来没那么清楚。
Hence, these patients are mistakenly called far sighted.
因此，这些患者被错误地认为是远视。
