What Is Peripheral Vision

Have you ever seen something out of the corner of your eye without moving your head? Well, that is known as peripheral vision, and works with central vision to make up your visual field.

Peripheral vision is what you see outside your central field of vision without turning your head. Peripheral vision loss can affect this ability, only allowing you to see what is in front of you, which will impact your sight. The degree of vision loss will depend on the causes, diagnosis and treatment.

If you wonder how peripheral vision works, what happens if you lose it, the causes behind it, possible treatments, and how to improve this capability, you should keep reading!

Anatomy of the eye

Before going into more detail on the topic, here is an illustration of the anatomy of the eye, which may give you a bit of context later on. 

• Cornea: a clear layer that protects the eye and helps focus your vision
• Iris: the colour of your eyes
• Pupil: the black dot in the middle of the iris, which contracts when it receives bright light and expands with dim light
• Lens: it focuses light and sends it to the back of the eye. It also sharpens sight
• Sclera: the white part of the eye that has a protective function
• Retina: a layer that contains special cells called rods and cones, which sense light and send it to your brain to form an image
• Macula: located at the centre of the retina, at the back of the eye, it helps you process objects in front of you
• Fovea: the small dip in the middle of the macula, where your vision has the most acuity
• Optic nerve: carries the information from the retina to the brain to transform the message into images
• Optic disc: where the retina connects with the optic nerve. As there are no rods or cones here, it creates a blind spot in your vision 

How does peripheral vision work?

To perceive the real world with high resolution, contrast, and colour saturation properties you need both healthy central and peripheral vision. 

On one hand, there is central vision which allows you to focus your attention on an object, person, or animal in the centre of your visual field. This vision has the highest visual acuity (sharpness and clarity). The macula is responsible for central vision; the fovea is what makes your eyesight sharp. However, this type of sight only covers a small area of the visual field, and the rest is covered by peripheral vision.^1,2

On the other hand, peripheral vision detects stimuli located on the outside or periphery of the visual field, which you should be able to observe from the corner of your eye without turning your head. The retina (excluding the macula) is responsible for this type of vision.^1,2

Why is peripheral vision useful?

While peripheral vision cannot help you clearly distinguish objects outside of your focal point, it can still provide you with useful information about your environment. Furthermore, it may be useful in tasks like monitoring our surroundings and planning saccades (rapid eye movements that shift your gaze) when an unexpected distraction emerges.³

For instance, while driving, peripheral vision is used to detect indicators, visual alerts, and other signs that help individuals prevent collisions, change lanes safely, and avoid accidents. In sports, athletes employ this type of sight to be aware of their opponents, teammates, and the situation.

Peripheral vision loss

If for some reason your peripheral vision becomes damaged, your perception of your surroundings as well as the way you interact with your environment might change.

What is tunnel vision?

When you have peripheral vision loss you are experiencing tunnel vision. This term is used because when tunnel vision occurs, your visual field becomes narrow, circular and tunnel-like, and you are only able to see objects that are right in front of you. While this could begin as a temporary problem, it may become permanent, depending on the cause or if it is not treated in time.

Peripheral vision loss symptoms

Usually, if you are experiencing peripheral vision loss you should be able to sense that something is going on. However, sometimes individuals are asymptomatic, or they might not present any symptoms during the early stages of this issue. If you are experiencing any of the following symptoms, you should consult an ophthalmologist:⁴

• Difficulty seeing in a dark condition
• Changes in visual acuity and colour vision
• Blurry sight
• Blind spots in central vision
• Disrupted perception of objects
• Bumping into people and objects

What causes peripheral vision reduction?

There are different reasons for these issues, ranging from mild conditions to diseases that could develop into permanent blindness if they are not treated immediately. Some causes include:^4,5

• Glaucoma
• Retinitis Pigmentosa
• Diabetes Mellitus
• Cataracts
• Choroidal neovascularization
• Stroke
• Retinal migraines
• Age
• Smoking
• Family history

How do you overcome peripheral vision loss?

If you are experiencing temporary peripheral vision loss because of retinal migraines, it will go away after a while. For other causes, you might need treatment, or if the problem is uncovered too late, the damage might be irreversible. 

Your doctor may prescribe you different types of treatment according to the cause behind this sight loss, which could include laser surgery, photodynamic therapy, eyedrops, vascular endothelial growth factor inhibitors, and vitamin supplements.^4,5

While you might not be able to completely prevent peripheral vision loss, there are some things you can do to slow it down:

• Consult a professional if you experience any of the mentioned symptoms
• Get regular eye examinations
• Wear eye protection (sunglasses)
• Maintain a healthy diet rich in fruits, vegetables and fibre⁶

Peripheral vision tests to diagnose problems

Not diagnosing and treating this condition on time may eventually lead to irreversible sight damage or even blindness. That is why it is important to keep track of your eyes' health, and thankfully several tests can detect peripheral vision problems. 

The best option is to go to an ophthalmologist and have a thorough eye exam, and more exams can be performed afterwards. These visual field tests measure how far on the sides you can see without moving your eyes, how sensitive your sight is in different areas of your visual field, and whether there are any blind spots in your vision. These visual tests are:

• Confrontation visual field test: with one eye covered, you focus on a point straight ahead whilst detecting the number of fingers the professional is holding up
• Automated perimetry test: you look at the centre of an instrument, called a perimeter, with one eye covered. You then track flashing lights that are displayed on the sides of your visual field
• Kinetic visual field test: similar to the perimetry test but with moving lights instead
• Goldmann field exam: Sitting away from a screen with a target on it, you will have to indicate when you detect an object moving in your peripheral vision

What can you do to maintain or improve your peripheral vision?

There are some things you can do to maintain your peripheral vision like:

• Look straight ahead, and move only your eyes to look at your sides or periphery. Then, take note of everything you have detected, and do a full scan of your location to see if you are right
• Perform the wall ball drill: focus on a point on your wall and without taking your eyes from it, throw a ball against said wall, and try and catch it without looking
• The straw and toothpicks exercise: use a marker to draw a horizontal line in the middle of the straw. Then, turn a glass upside down and stick the straw to the bottom of it (this is so the straw does not move while you are doing this activity). Grab a toothpick in each hand while focusing on the drawn line, and insert each toothpick, at the same time, into the ends of the straw without moving your eyes

FAQ’S

Can you drive if you lose your peripheral vision?

You need overall good vision to be able to drive. If your peripheral vision is highly damaged, it could be extremely dangerous to drive, as you might not detect other vehicles, hazard signs, walkers or other important factors. If you are experiencing this visual problem, you should ask your doctor if you should drive.

How accurate is your peripheral vision?

While your peripheral vision encompasses 99% of your visual field, this sight has low resolution, meaning you do not see objects in your periphery as clearly.

Are you considered blind if you have no peripheral vision?

You are considered blind if you lose 100% of your vision, however, if only your peripheral vision is no longer present, you may be considered partially blind.

Summary

Peripheral vision is your ability to see the edges of your visual field without having to turn your head. This type of sight, along with central vision (what you see in front of you), ensures clear and sharp sight. However, macular damage or other diseases could impair peripheral vision, causing you to experience tunnel vision. This will affect the way you perceive and interact with your environment. While in some cases this is temporary, in others, the damage could turn into blindness if not treated in time. That is why it is important to have eye tests, including peripheral vision exams to ensure there is no underlying visual issue going on. Moreover, performing certain exercises could help you maintain and improve your peripheral vision.