Causes of Tunnel Vision
The list of possible causes for loss of peripheral vision is a long one, so this article should by no means be taken as an exhaustive list. If you find you have experienced a decrease in your peripheral vision, it is important that you see an eye doctor as soon as possible in order to obtain a diagnosis and find out what treatment options may be available to you.
Glaucoma is one of the leading medical causes of tunnel vision. This insidious disease is caused by a buildup of pressure inside the eye (which itself can have any number of causes), which eventually begins to cause damage to the optic nerve. When this happens, blind spots begin to appear on the affected person’s field of vision.
Open-angle glaucoma, the most common type, is also the form of glaucoma most likely to cause tunnel vision. This is because the blind areas in the visual field caused by open-angle glaucoma tend to appear first at the edge of the affected person’s range of sight.
If you believe you are experiencing any of the symptoms of glaucoma—which include (in addition to tunnel vision) cloudy or blurred vision, severe eye pain, halos around lights, and nausea/vomiting, it is important that you seek medical attention as soon as it is possible to do so.
Retinitis pigmentosa is a progressive disease that causes the death of the rods and cones—the light-sensitive cells in your retina that pick up visual information and transmit it to your brain. This causes a gradual loss of vision, which often begins with peripheral vision loss.
Unfortunately, the cause of retinitis pigmentosa is not known (although it is suspected to be genetic), and there is no cure.
Blood Loss Due to Injury
Under certain circumstance, the rapid loss of a large amount of blood can result in a loss of peripheral vision.
Drinking too much alcohol can cause a variety of visual symptoms, including blurred vision and double vision. While it is less common, alcohol intoxication can on occasion cause tunnel vision.
Of course, this is a subjective experience; in many cases of alcohol-induced peripheral vision loss, the likely explanation is that the intoxicated person is simply suffering from a decreased awareness of their surroundings, and a correspondingly decreased ability to react to them. In short, a drunk may have his peripheral vision and simply be too intoxicated to pay any attention to it.
Hallucinogenic Drugs come in a great many varieties: LSD (aka “acid”), psilocybin (aka “magic mushrooms”), ecstasy, peyote buttons, Mexican Moonshot Capsules, Squid Juice, Midnight Deathtrap Music, Symbionese Liberation tablets—the list is endless.
What most of the chemical concoctions have in common is their ability to alter the user’s perceptions and cause visual hallucinations—which can sometimes include tunnel vision. One reason for this may be that a person who is “tripping” on psychedelic drugs may become intensely focused on whatever has captivated his attention—say, a pebble or an insect. This narrowing of mental focus creates the sensation that object being focused upon is the only thing in the world, a perception that may manifest itself as tunnel vision.
While experimenting with so-called “psychedelic” drugs may seem like fun, it is not a practice recommended by most mental health professionals. Your brain is not a toy; it is one of the more important organs in your body, and needs to be treated accordingly.
Leaving aside the effects of alcohol and recreational psychedelics, more mundane drugs can also sometimes cause tunnel vision. Medications such as brimonidine, nitroglycerin, and scopolamine, among many others, list peripheral vision loss among their side effects. Always consult with your doctor and your pharmacist about potential side effects before beginning any course of medication.
Concussion or Stroke
Over half a million Americans suffer strokes each year. The symptoms of a both conditions include dizziness, feelings of confusion, and various visual disturbances, including peripheral vision loss. The reason for this is that stroke and concussion are both negative events affecting the brain (a stroke occurs when blood flow to the brain is blocked, depriving the brain of oxygen and nutrients).
Choroideremia is an extremely rare genetic condition that causes sufferers to slowly lose their vision. It affects men almost to the exclusion of women, and symptoms usually begin to manifest during childhood.
Sufferers of choroideremia find their vision slowly dimming over a period of years, and eventually their peripheral vision begins to disappear.
Retinal detachment occurs when the retina—the layer of light-sensitive cells at the back of the eye—peels away from the back of the eye, in much the same way that an orange peel disengages from the fruit.
Visual symptoms of retinal detachment include flashes and floaters in the peripheral vision area, and the visual field can sometimes narrow, causing peripheral vision loss.
Retinal detachment is a serious, vision-threatening emergency. If you think you may be experiencing any of the symptoms of Retinal detachment, see an eye doctor as soon as you possibly can.
Many people are subject to panic attacks. This is not a character weakness; it is a medical condition with both psychological and physiological causes.
Among the symptoms of panic attack are derealization, which is defined as a feeling of unreality, and depersonalization—a sense of detachment from oneself. With these sensations can come a range of vivid perceptions of altered reality, including tunnel vision.
A cataract occurs when some of the protein that makes up the lens of your eye begins to clump together, causing a cloudy area in your field of vision. Often cataracts form in the center of the lens (this is called a nuclear cataract), but in many cases cataracts form around the edges of the lens, causing peripheral vision loss.
Ocular migraines are not the same as the migraine headaches that you or someone you know may experience from time to time. In fact, an ocular migraine is often painless.
A person who suffers an ocular migraine will, for ten to twenty minutes, experience shimmering “scintillations” in their visual field, possibly accompanied by halos around objects and a loss of peripheral vision.
Fortunately, ocular migraines are harmless, and the sensation of tunnel vision and other symptoms abate within minutes.
Mercury is a highly poisonous substance, and mercury poisoning can happen in a variety of ways. Industrial pollution is one of the more common causes of mercury poisoning, but equally common—and more widely known about—is overconsumption of mercury-contaminated fish or whale meat.
Many of the symptoms of mercury poisoning are neurological in nature—itching, burning, or the sensation of insects crawling on one’s skin—and visual disturbances such as tunnel vision can certainly accompany these types of symptoms.
There are many, many different varieties of poisonous snake in the world, with many different types of venom. The type of snake venom that concerns us here is neurotoxic venom. This is any snake venom that acts on the nervous system. The neurotoxins in snake venom produce a number of unpleasant effects, including trouble swallowing, respiratory failure, and peripheral vision loss.
Which variety of snake is most likely to be armed with neurotoxic venom? Elapid snakes, i.e., cobras. There are exceptions, however—the venom of the Mojave rattlesnake is also highly neurotoxic. If you enjoy hiking or other such outdoor activity, it is important to exercise caution: always wear long pants and sturdy boots, and watch the trail carefully.
Risks Associated with Peripheral Vision Loss
The loss of one’s peripheral vision, even if temporary, can present immediate and long-term safety hazards. Without our peripheral vision, we are unable to perceive dangers that are not directly in front of us.
The most important thing to remember is that never, under any circumstances, should you drive a car if you are experiencing tunnel vision. This cannot be stressed enough. It is likewise important that you not ride a bicycle with tunnel vision, especially in vehicular traffic.
If you must go somewhere on foot, and your peripheral vision is impaired, the wisest and safest course of action is to ask a friend or family member to accompany you on your errand. Take your friend’s arm and hold firmly but loosely onto their elbow or bicep. Your companion will serve as an additional pair of eyes, ensuring that you are not blindsided by oncoming cars or bicycles that you are not able to see due to your tunnel vision.
Also, while this should go without saying, it bears mentioning that if you have a job that involves physical labor, especially if it requires you to use potentially dangerous tools or heavy machinery, you must take a leave of absence from that job until your normal peripheral vision has been restored. If your tunnel vision is permanent for any reason, a career change or an application for disability payment may be in order.
Likewise, if your hobbies include sporting activities such as baseball, basketball, boxing, or—most especially—target shooting, you must abstain from these activities until your tunnel vision has cleared up.
Treatment for Tunnel Vision
The correct treatment for a case of peripheral vision loss depends entirely on the cause of the condition. The articles on our site linked from the “Causes” section above can shed light on what (if anything) can be done to treat your particular case of tunnel vision.