tunnel vision

Tunnel vision is a lack or loss of peripheral vision that only allows you to see objects directly in front of you. You can simulate severe tunnel vision by covering one eye and using the other to look through the cardboard tube of a roll of paper towels. Often, peripheral vision loss that leads to tunnel vision may occur gradually. By the time you realize you no longer have a normal field of view, your tunnel vision may already be permanent and irreversible. Your field of view (or visual field ) is the extent of the observable world that your eyes can see at any given moment. Essentially, the objects you focus your eyes on (like the letters on an eye chart ) comprise your central vision . Nearly all the rest of your visual field is considered peripheral vision . Tunnel vision is a particular type of visual field defect where all quadrants of the visual field are constricted (reduced in size). In other words, your peripheral vision in all directions (out, in, up and down) shrinks. The 360-degree loss of peripheral vision becomes the dark “tunnel” of your tunnel vision. Complete tunnel vision mostly develops in a gradual process; however, depending on the cause of the reduced visual field, tunnel vision can also occur in a sudden onset. Migraines can cause temporary tunnel vision. If present, migraine-related vision disturbances (including peripheral vision loss) typically last only 20 to 30 minutes. Many cases of non-migraine tunnel vision and peripheral vision loss are permanent and irreversible. One possible exception may be early vision loss from certain types of stroke in the brain. For example, a stroke affecting the visual cortex causes peripheral vision loss called hemianopia or cortically induced blindness . In some cases, peripheral vision may improve spontaneously within the first few months after a stroke of this kind. Any permanent loss of sight can significantly affect your quality of life and mental health. If you have tunnel vision, consider consulting a mental health professional for advice on how to cope with this major life change. Be aware that peripheral vision loss can also affect your ability to drive safely. This may prevent you from being able to keep, renew or obtain a driver’s license — even if you can still see 20/20 on an eye chart. Though regular eyeglasses and contact lenses will not correct peripheral vision loss, certain low vision devices, such as magnifiers and telescopic glasses, can be helpful. For example, special prism glasses can help expand your side vision if you have certain types of peripheral vision loss. Some types of tunnel vision and peripheral vision loss may be preventable. Prevention and early detection are key when it comes to peripheral vision loss. It is recommended to get a yearly physical, an annual eye exam, and follow the advice of your primary care physician and eye doctor. Double vision is seeing two images of an object instead of one. Also called diplopia, it can occur suddenly and have serious causes. Double vision (diplopia) is one of several vision problems that can occur after a stroke. Double vision treatment is determined by the condition causing it. Learn more about the different forms of treatment and correction. Learn about the different types of double vision —monocular, binocular, horizontal, vertical and more — and what each can indicate about your overall health. Halos can appear around lights when you look directly at them. Causes of halos can be minor, like outdated vision prescriptions, or serious, like cataracts. Phosphenes (seeing stars) are lights and colors that result from internal stimulation of the eye rather than external light. Starbursts can appear around bright lights, usually at night, when certain vision conditions or treatments change the way light enters the eyes.