Understanding Tunnel Vision

The term "tunnel vision" describes a restricted field of vision where you can see straight ahead, but the vision to the sides—called peripheral vision—is lost. Having tunnel vision, also known as peripheral vision loss, is much like looking through a narrow tube.

There are many causes of tunnel vision, including diseases of the eyes or optic nerve (such as glaucoma or optic neuritis) or an injury to the brain (such as a stroke or traumatic head injury). The treatment varies by the cause.

This article describes the symptoms and causes of tunnel vision, including the signs of a medical emergency. It also explains how to cope with a condition that affects 13% of adults over 65.

What Tunnel Vision Feels Like

The main symptom of tunnel vision is the loss of peripheral vision. Peripheral vision is the field of vision outside of the center of your gaze.

Peripheral vision plays an important role in sensing motion outside your direct line of sight without turning your head. This helps with driving, playing sports, and generally moving around without bumping into things.

The most obvious sign of tunnel vision syndrome is obscured peripheral vision in one or both eyes. Other signs of tunnel vision include:

• Having to turn your head to see things at your side
• Bumping into objects outside of your field of vision, including door frames and steps
• Trouble seeing at night
• Having to drive your car slower to keep in your lane
• Difficulty navigating in dim lighting, such as in a dark movie theater
• Difficulty catching things tossed at you
• Feeling startled by things approaching you from the sides

Depending on the cause, you may also experience blurred vision.

What Causes Tunnel Vision?

Tunnel vision can affect anyone of any age but is more common in older adults whose vision may be naturally deteriorating.

Many conditions can lead to tunnel vision, including:

• Retinal detachment: An emergency medical condition in which the retina becomes separated from the blood vessels that provide it with oxygen
• Glaucoma: A group of conditions typically associated with high intraocular (inner eye) pressure that can lead to blindness if left untreated
• Retinitis pigmentosa: A rare inherited eye disease that causes damage to the retina
• Optic neuritis: Inflammation of the optic nerve caused by viral diseases like mumps and measles, autoimmune diseases like multiple sclerosis, and other inflammatory conditions
• Diabetic retinopathy: A condition that can cause vision loss due to uncontrolled diabetes
• Severe cataracts: Clouding of the lens of the eye that can cause tunnel vision when severe
• Traumatic brain injury; Most often due to a focal injury involving a blow or impact to the head
• Stroke: Caused by either a blockage or rupture of a blood vessel servicing the brain
• Migraine: Particularly migraines with aura
• Pituitary tumors: Abnormal growths, typically benign, that can press on the optic nerve
• Pseudotumor cerebri: Also known as a false brain tumor caused by the buildup of fluid around the brain and spinal cord
• Hallucinogenic drugs: Particularly dissociative drugs like ketamine
• Sleep deprivation: When you do not get enough sleep to meet the body's needs
• Panic attack: A brief episode of intense anxiety that causes physical sensations like vision changes
• Syncope: The temporary loss of consciousness, also known as fainting
• Altitude sickness: Caused by the lack of oxygen to the brain

True tunnel vision is most often associated with severe glaucoma, retinitis pigmentosa, and retinal detachment. 

How Is Tunnel Vision Diagnosed?

Tunnel vision is diagnosed by the loss of peripheral vision. The underlying cause requires an evaluation by an eye specialist known as an ophthalmologist.

Certain tell-tale symptoms can hint at the underlying cause, including whether one or both eyes are affected, if the onset was sudden or gradual, or if other parts of the eye are dysfunctional (such as your pupils).

The following tests may be ordered to narrow the causes and direct the appropriate treatment:

• Confrontation visual field test: This machine displays different objects within your peripheral field of vision to see if you can identify them.
• Automated perimetry: This special instrument evaluates how you respond to blinking lights in your peripheral field of vision. This helps create a detailed map of your visual field.
• Humphrey visual field (HVT) test: This advanced test uses computerized technology to assess the entire extent of your peripheral field of vision.
• Fluorescein angiography: This imaging test uses a special camera and an injected dye to check for abnormalities in blood circulation in your eye.
• Optical coherence tomography (OCT): This imaging study uses reflected light to create a highly detailed cross-sectional image of your retina.
  

How Tunnel Vision Is Treated

The treatment of tunnel vision varies based on the underlying cause. While some causes are highly treatable, others are not and need to be managed over the long term.

Prescription Eyewear

Tunnel vision cannot be treated with conventional eyeglasses or contact lenses. However, there are prescription lenses, known as prism lenses, that can be added to eyeglasses to expand the field of vision.

Prism lenses redirect the light into the retina to make images align. They are useful for treating tunnel vision associated with:

• Stroke
• Migraine 
• Traumatic brain injury
• Pituitary tumors

Medications

There are medications that can help correct tunnel vision caused by conditions like glaucoma and optic neuritis.

Examples include:

• Timoptic (timolol ophthalmic solution): A beta-blocker drug delivered in eyedrop form that helps reduce blood pressure inside the eye
• Antihypertensive drugs: Oral drugs like beta-blockers, diuretics, and calcium channel blockers used to reduce high blood pressure
• Intravenous corticosteroids: Steroid drugs like prednisone delivered intravenously (into a vein) to reduce inflammation associated with optic neuritis
• Anxiolytic drugs: Oral drugs like Xanax (alprazolam) used to ease anxiety in people prone to panic attacks

Eye Procedures

When prism lenses and medications fail to provide relief, more invasive procedures may be recommended to correct tunnel vision.

These include:

• Laser eye surgery: Suitable for correcting problems like glaucoma, diabetic retinopathy, and retinal detachment
• Electronic retinal implant: An implanted device can stimulate normal retinal function in people with retinitis pigmentosa
• Vitrectomy: A surgery used to treat blood vessel leakage in people with diabetic retinopathy and retinal detachment
• Trabeculectomy: A surgery that drains fluid from the eye to reduce pressure in people with severe glaucoma
  

Coping With Tunnel Vision

It’s important to treat the underlying cause of tunnel vision if possible. You can also use coping strategies like these:

• See your eye doctor on a regular basis to ensure your eyes are healthy.
• Keep potentially dangerous furniture or objects put away to ensure your home is as safe to navigate as possible.
• Consider joining a support group to connect with others going through similar experiences.
• See a visual rehabilitation specialist who treats people with low vision
• Meet with an orientation and mobility specialist who helps individuals with visual impairments move about safely, confidently, and independently 
• See a mental health professional to manage anxiety or depression

Summary

Tunnel vision, or loss of peripheral vision, is most often caused by eye conditions like glaucoma or a detached retina. Other conditions can also lead to tunnel vision. including stroke. migraine, multiple sclerosis, and anxiety.

Tunnel vision can impact your ability to navigate your environment and make certain tasks, such as driving or walking at night, difficult to dangerous. Tunnel vision can often be resolved by treating the underlying cause.