What is tunnel vision?
Peripheral vision is the part of your vision that lies beyond your direct line of sight – it’s what we see at the side or edge of our vision. Tunnel vision means the worsening or loss of this peripheral vision and can be temporary, or permanent.
Signs and symptoms of tunnel vision
Without your side vision, it will look as if you’re looking through a tunnel. So you would only be able to see things in a small circle directly in front of you.
Tunnel vision causes
There are many possible causes of tunnel vision, and this list is not conclusive.
The outer part of the retina forms our peripheral vision – any damage to this part of the retina would cause a loss in that area of vision. Retinitis pigmentosa is a very rare genetic condition known to cause tunnel vision.
Optic nerve damage
The optic nerve is responsible for sending signals from the eyes onto the brain to produce the images we see. Tunnel vision can happen when the optic nerve is damaged.
Glaucoma is a common eye disease that affects the optic nerve, and its symptoms include a slow deterioration in peripheral vision. Left untreated, it can lead to tunnel vision or even sight loss – that’s why regular eye tests are so important.
Damage to the brain
Things like blood loss on the brain or a stroke could also cause a loss of peripheral vision.
Temporary tunnel vision
Tunnel vision can happen temporarily in cases like extreme panic, stress or anger, when the body will produce high levels of adrenaline. Usually, normal vision will be restored without needing any treatment. Use of alcohol and drugs have also shown to affect peripheral vision.
If you do experience a loss of peripheral vision, you should go to your GP or local casualty department as soon as possible.
How tunnel vision is diagnosed
Tunnel vision can be diagnosed through a visual field test, which is included as part of your normal eye test. This will check for any blank spots in the vision by testing the area of the retina which sees our peripheral vision.
You’ll be asked to look at a small central light on a blank screen with one eye at a time. A series of lights will briefly flash around the screen and you’ll be asked to just press a button every time you see a flash. Each part of the retina is tested to give us an idea of how normal your peripheral vision is.
Risks of tunnel vision
Tunnel vision can be particularly dangerous for things like driving or cycling, as without having your full peripheral vision, you won’t be able to recognise potential dangers unless they are directly in front of you. So if you’re experiencing any symptoms of tunnel vision, it’s important you get it checked by your GP or optician as soon as possible.
Treatments for tunnel vision
Treating tunnel vision will depend on its underlying cause. Your optician or GP will be able to determine the cause and recommend the best treatment for you.
If you think you have a loss of peripheral vision, it’s important you get it checked by your optician. If you experience sudden peripheral vision loss, you should seek advice immediately from your optician, GP or local casualty department.
Try to go with someone to help to guide you and make sure to take extra care when crossing roads.
Did you know?
Tunnel vision can have a number of different causes and is usually fleeting. If this isn't the case, or if you are concerned, contact your optician or GP as soon as possible.