One of the major misconceptions about visual impairments is that it means someone cannot see at all. In fact, while many people with vision problems will be said to have 20/200 vision, the actual range of sight issues they have can vary quite considerably. For some people it may mean complete loss of sight, but for others, it can mean a wide range of issues that severely restrict their vision in different ways. One of the more common of those is peripheral vision loss, which is often referred to as tunnel vision. But what is peripheral vision, what causes the loss, and how can we prevent it?
Common Causes of Peripheral Vision Problems
Eye diseases are a significant issue for anyone because even minor problems can result in long term vision challenges, and they are the main causes of peripheral vision problems. These include:
- Glaucoma – A disease of the optic nerve that can cause a number of vision issues.
- Retinal eye diseases – Including macular degeneration, retinitis pigmentosa, retinal vein occlusion, optic neuritis and diabetes-related retinopathy
- Stroke –Loss of peripheral vision can be a lasting effect after a stroke.
- Migraine Headaches
- Concussion
- Hypertension
- Some types of artery disease
Glaucoma and various retinal eye diseases tend to cause permanent peripheral vision loss, however in the case of many of these illnesses and diseases, the tunnel vision effect may be temporary. In all cases it is crucial that professional medical help is sought immediately to ensure that everything that can be done to mitigate the issue is put into practice.
Symptoms of Peripheral Vision Problems
In most cases, peripheral vision loss doesn’t happen immediately, and is a gradual process that gets progressively worse over time. Peripheral vision problems are not always easy to recognize though, as they affect your field of vision (FOV), but in a very specific way. There are two types of vision that make up how we see the world around us with healthy vision, the first is central vision. This refers to the objects that are directly in front of you, that are in the center of your vision when your eyes are pointed at something. This is where the eyes focus, which is why objects in this central vision are sharper and clearer than anywhere else in your vision range, even if you have completely healthy eyesight.
The second type of vision is peripheral vision. This is the areas surrounding that central vision area, where your eyes are not as tightly focused, that tends to be a little less sharp. Sometimes called side vision, it is what we see from the corner of our eyes, and can be incredibly useful when driving, riding a bike or any number of other activities.
受周边视力丧失影响的是视力的第二个区域，即您的周边视力。开始时，外围视力可能会变得模糊，也可能只是边缘看起来更暗，从而缩小了视野范围，使您能看到的东西比平时少。.
As you lose side vision, so the width of your overall vision decreases and you can see little beyond that central vision area, this is known as the tunnel vision effect. This is because it mimics the effect of standing in a dark tunnel looking out of the opening at bright sunlight. You see that central part clearly, but everything else is dark, indistinct and lacking in clarity.
这就是周边视力丧失的影响，如果您发现有任何问题出现，即使看起来很轻微，也一定要寻求医疗帮助。如果您有任何顾虑，可以向眼科专家咨询周边视力测试，但好消息是，许多类型的周边视力问题都是可以治疗的，而且可以通过选择合理的生活方式来完全避免造成周边视力问题的一些原因。.
Peripheral Vision Tests
The best way to maintain your eye health and prevent eye diseases of all kinds, including the loss of peripheral vision, is by having regular eye exams. These allow your ophthalmologist to spot problems early, and with a treatable problem like tunnel vision that can make all the difference. This is especially true for anyone suffering from diabetes, where annual eye exams should be a minimum, and can often be the different in treating your vision problems.
There are three types of eye test that can be useful in dealing with peripheral vision issues, these are:
对抗视觉测试
A simple test most people will be familiar with, it involves covering one eye and having the doctor or eye care technician hold up fingers for you to count within your peripheral vision. This is then repeated with the other eye. Simple and easy to administer, it gives a broad idea of the level of side vision someone has, however as it used no instruments for measurement, it may not always catch small side vision defects.
Automated Static Perimetry test
该测试使用一种专门用于测试周边视力的设备，即周边视力计。患者的一只眼睛被遮住，每当看到灯光出现时，就被要求按下一个按钮。这些光位于中心视力和侧视视力区域的四周，以随机顺序出现。一只眼睛完成测试后，另一只眼睛再重复一次。如果没有注意到某些灯光出现的时间，就会凸显出某些区域的周边视力下降，从而让眼科医生进行进一步的检查。这项测试对识别青光眼引起的问题特别有用。.
动力学视觉测试
The last type of peripheral vision test, which also uses the same dedicated perimeter machine as the previous test. Here though, light moves in and out of your side vision, rather than appearing in one place and disappearing after. This approach allows a more accurate understanding of where the issues with peripheral vision begin in terms of the field of view, and are particularly useful for diagnosing retinal diseases and neuro ophthalmological issues.
视力健康也与您的整体健康息息相关，因此合理饮食、多做运动以及健康的生活方式都会对视力健康产生巨大的影响。保护眼睛也是其中的一部分，但由于许多导致暂时性周边视力丧失的问题都与整体健康状况不佳有关，因此努力保持更健康的生活方式确实也是保护眼睛健康的最佳方法。.
However, while taking care of yourself is great advice, with regular eye exams to identify issues early, you may still find problems that need treating. Tunnel vision is one of the more common eye diseases we suffer from, and as a result there is extensive medical understanding of the disease and its treatment.
In general, tunnel vision is treated by dealing with the underlying issue that is causing it. Whether that is glaucoma, retinal diseases and so on, by solving this issue in a large number of cases, the loss of peripheral vision is also resolved too. In a similar way, issues caused by strokes, hypertension, concussion and migraines tend to be temporary too, and as the underlying issue is dealt with, so the vision health issue will be too.
然而，在某些情况下，周边视力丧失是永久性的，这时的目标是帮助患者控制病情，尽可能将影响降到最低。Acesight 电子眼镜系列中的助视器，如 Acesight 和 Acesight VR，能够为周边视力丧失者提供帮助。这种助视器配备了窄模式功能，允许用户将屏幕移动到合适的位置，以适应隧道视觉的情况。有关 Acesight 和 Acesight VR 电子眼镜的更多信息，请访问官方网站： https://www.acesight.com/. .在多种技术的帮助下，周边视觉问题可以得到有效控制，让视力为 20/200 的人能够保持自己的生活方式和独立性。.
参考资料
https://my.clevelandclinic.org/health/symptoms/24435-tunnel-vision-peripheral-vision-loss
https://dmei.org/blog/peripheral-vision-loss-what-is-it-and-how-to-treat-it/
https://www.aao.org/eye-health/symptoms/vision-loss-peripheral-side
