Imagine looking straight ahead through a peephole, viewing everything through it, up, down, left, right, as far as you can see.
Now imagine that peephole getting smaller and smaller after every few hours, continually restricting your field of vision, allowing you to see everything straight ahead of you, but blacking out above, below and around.
This might lead you to believe that you are looking through a narrow tube or a tunnel and this is how people suffering from ‘tunnel vision’ feel, a condition also referred commonly as the loss of your peripheral vision.
What Describes Peripheral Vision?
Peripheral vision can be described as everything you see on the side while looking straight ahead and without turning your head sideways – and when this ability of yours is diminished, it is referred as ‘tunnel vision’ or ‘peripheral vision loss’.
A damaged optic nerve, retina or the areas of the brain responsible for processing visual input, individually or collectively, deteriorating the normal wide-angle of your field of vision, can lead you to peripheral vision loss. And loss of peripheral vision in all directions is what tunnel vision is all about.
You can lose peripheral vision at any age, though the likelihood of elder people getting affected by it is much higher because of the higher number of underlying conditions linked to various eye problems capable of leading them to tunnel vision.
While tunnel vision affects most of the people permanently, there are also certain situations where it affects people on temporary basis. Many people suffering from migraine headaches, for instance, report suffering from tunnel vision temporarily. Moreover, it can affect either one of your eyes or both.
Symptoms of Tunnel Vision / Peripheral Vision Loss
Inability or impairment of the side vision being the major symptom of tunnel vision, there are a handful of other symptoms indicating its presence in your eye(s). Some of them are:
- Seeing glare or halos around lights and other illuminated objects
- Unusual pupil size
- Increased or decreased sensitivity to light
- Impaired night vision
- Redness, soreness or swelling in one or both eyes
Sometimes, certain other symptoms including headaches, nausea and vomiting also appear along with loss of peripheral vision.
Testing Peripheral Vision
To rule out the presence of tunnel vision in a person, comprehensive peripheral vision test is required under the supervision of an eye doctor, who can use different approaches to determine the extent of peripheral vision loss. Three most commonly used approaches to do so include:
Automated Perimetry: This involves you sitting in front of a dome, staring at an object in its center. Then you need to press a button whenever you see small flashes of light with your vision focused on that object and your head remaining still.
Confrontation Visual Field: In this approach, you sit in front of a doctor. With one eye covered at a time and staring straight ahead, you have to respond to the doctor when you see their hand moving before you.
Tangent Screen or Goldman Field: This particular test requires you sitting about 3 feet apart from a screen with a target in its middle. You need to focus on the described target and let the doctor know whenever you notice a moving object within your peripheral view.
For these tests, no special preparations are needed, nor are there any particular side effects associated with them. Poor results of these tests simply mean that additional tests need to be taken to determine the presence of a probable eye disease (glaucoma, for example) potentially responsible for tunnel vision.
Causes of Peripheral Vision Loss
A number of underlying conditions can be held responsible for peripheral vision loss, some of them just affecting the eyes, while others also affecting the brain or certain other body parts.
Moreover, some lifestyle choices can also contribute to different types of vision problems. The list given below highlights some of the potential causes of tunnel vision.
Glaucoma: Known as one of the leading causes behind peripheral vision loss, glaucoma is caused due to increased pressure building up inside the retina. This ultimately damages the optic nerve, resulting in inflicting a person with tunnel vision.
Retinitis Pigmentosa: A disease that progressively damages the cells in the retina, which serve the function of picking up and transmitting all visual information to the brain.
Cataracts: This is the result of clumping together of protein that makes up eye lens, creating a cloudy area within the lens.
Ocular Migraine: These are often painless, unlike the headaches caused by typical migraines, but can potentially lead to peripheral vision loss.
Retinal Detachment: Tunnel vision can also occur as a result of retinal detachment, the phenomenon of peeling away of the layer of sensitive cells found at the back of the retina.
Stroke: Stroke affects over half a million people across the U.S. every year, inflicting various health issues including peripheral vision loss.
Choroidermia: A rare genetic condition known to lead a person to a gradual vision loss, which begins with slow dimming of peripheral vision until it disappears completely.
Intoxication: Excessive alcohol consumption can also lead to peripheral vision loss.
Diagnosis of Peripheral Vision Loss
You’ll get a visual field test from your doctor aimed at checking blank spots in your vision, most probably, never even noticed by you yet.
You’ll need to sit across a bowl shaped device, with your face right in front of it and wear a patch over either of your eyes, one at a time, to get them checked individually. You’ll be advised to stay hold your head still with vision focused straight ahead. Then you have to press a button whenever you see flashes of light at different points around the bowl, without tilting your head sideways to see them.
Your eye doctor might repeat the test periodically (every 6-12 months), if you suffer from any eye disease, to observe any noticeable changes in your vision.
Peripheral Vision Loss Prevention
Prevention against peripheral vision loss is not much of a possibility, according to the research, but taking control of some of the conditions leading to it is certainly one of the best ways to stay away from becoming a victim of tunnel vision.
For instance, if you’re an African-American aged 60 or above, or glaucoma is known to run in your family, your chances of getting glaucoma are raised quite significantly, which can become a reason for you to suffer from peripheral vision loss.
What you can do is lower your chances of becoming a victim of glaucoma by consulting your eye doctor for a comprehensive eye exam when you turn 40 or above, repeating it every 2 to 4 years.
Similarly, you can start wearing protective goggles if you engage in sports activities or like working around your house, because eye injuries can also lead to glaucoma, one of the reasons behind peripheral vision loss.
Peripheral Vision Loss Treatment
Peripheral vision loss cannot be treated if it is inflicted upon you because of glaucoma or RP, but tending to it proactively and slowing down or stopping the damage done by it is certainly a highly advisable proposition. For example, if you practice yoga, make sure not to get into poses that can result in raising eye pressure, such as headstand or handstand.
If you suffer from permanent loss of peripheral vision, prioritize visiting a low vision specialist who can assess your visual impairment comprehensively and advise you about specialized low vision aids capable of assisting you with your mobility issues caused by tunnel vision.