Can Even MINOR Bumps On The Head Cause BVD?

If you suffer a head impact of any severity, the correct action to take at the time is to seek medical attention. But what if that bump you barely thought twice about leads to vision symptoms that persist 2-4 weeks later?

I’m Paul Graham, Owner and Principal Optometrist at Harmony Vision Care on the Gold Coast. Binocular vision dysfunction (BVD) is something we’re asked about fairly often after a head injury, particularly when the incident itself seemed minor and the visual symptoms took a while to surface.

This article looks at how something as ordinary as a bump on the head can quietly affect the way your eyes coordinate, and why that connection is often missed entirely.

Key Takeaways

• A minor head bump can sometimes affect eye focusing, movement and coordination, even without direct eye injury.
• Visual symptoms after a head injury don’t always become noticeable right away. They may emerge later as you return to normal activities.
• Headaches, dizziness or blurred vision after a head injury can have several causes, not just BVD.

How Can A Minor Head Bump Lead To Vision Problems?

A minor head impact can sometimes affect the systems that control how your eyes focus, move and work together, even when your eyes themselves haven’t been injured.

BVD is an umbrella term some clinicians use to describe problems involving the coordination of the two eyes. After a head injury, that coordination can become less efficient. You might find it harder to keep words clear while reading, follow moving objects, or maintain comfortable vision over longer periods.

The size of the bump doesn’t necessarily predict the severity of the visual symptoms that follow. A collision during sport, for example, may look relatively uneventful but still be followed by noticeable changes in visual comfort.

There’s another possibility we need to consider. Some people may have had a mild eye coordination problem for years without knowing it, because their visual system compensated successfully. A head injury could make that compensation harder to maintain, which is when symptoms become noticeable. This is different from assuming the injury created the problem from scratch.

What Sort Of Injuries Can Lead To Vision Problems?

Even a relatively minor knock can sometimes be followed by changes in how comfortably your eyes work together.

It might be a fall, a collision playing sport, bumping your head on a cupboard, or a relatively minor vehicle accident. The event doesn’t need to involve an obvious injury to the eyes themselves.

Immediately afterwards, most people are understandably more focused on pain, bruising or the shock of what happened, so subtle changes in vision can be easy to miss in the moment.

A concussion is one possible consequence of head trauma, but symptoms vary considerably from person to person. Visual difficulties can occur alongside other post-injury symptoms, so we don’t assume that problems such as headaches, dizziness or blurred vision automatically mean BVD. The circumstances matter, but so do the symptoms that follow.

Could My Vision Problems Start Some Time After I Hit My Head?

Yes. Some people notice visual changes immediately after a head injury, while others become aware of them later as they return to normal activities.

The delay makes sense once you consider the demands involved. Resting at home places very different demands on your vision compared with reading, working on a computer, driving or playing sport. A problem may become more noticeable once your eyes are asked to work harder again.

This can make the connection surprisingly easy to miss. Headaches, visual fatigue or difficulty concentrating might initially be put down to stress, tiredness or too much screen time, and the earlier bump can seem too insignificant to be relevant. That’s exactly why we ask about previous head injuries when investigating new visual symptoms, including incidents that seemed minor at the time. Sometimes the timeline provides an important clue.

What BVD Symptoms Should I Look Out For?

Symptoms associated with binocular vision difficulties after a head injury might include:

• Double vision or intermittent blur
• Headaches, eyestrain or visual fatigue
• Losing your place or rereading the same line while reading
• Needing breaks sooner than you used to during near work
• Dizziness, motion sensitivity or feeling disoriented, particularly in visually busy places like supermarkets or crowds, while scrolling on a screen, or watching moving traffic

None of these symptoms on their own confirm that you have BVD, and it’s important not to read this as a checklist. These symptoms are commonly reported after head injuries but can have many other causes.

Reading often brings the earliest clues. Problems with eye teaming, focusing or the eye movements involved in moving from word to word can make a previously easy task surprisingly tiring. Dizziness and disorientation are relevant too. Vision and balance are closely connected, so we consider these as part of the wider clinical picture rather than in isolation.

There’s one more distinction worth making. It’s possible to read every letter on a standard eye chart and still have difficulty coordinating your eyes comfortably. Clear eyesight and comfortable binocular vision aren’t the same thing.

How Can An Optometrist Determine Whether My Symptoms Are BVD?

An optometrist can investigate possible BVD by assessing how your eyes coordinate, focus and move together, rather than relying on how clearly you can read an eye chart.

We look at factors such as eye alignment, convergence and focusing, and we assess the eye movements involved in shifting your gaze between targets and following something that moves. These tests help build a picture of how your visual system is functioning.

Finding an abnormal result doesn’t automatically explain your symptoms, though. We need to consider whether the clinical findings actually fit what you’re experiencing in everyday life, since headaches, dizziness, blurred vision and difficulty concentrating after a head injury can also occur with concussion, vestibular problems, neurological conditions and other health issues. That wider context matters. We don’t want to label every headache after a bump as BVD simply because the timing appears to fit.

Some symptoms also warrant medical assessment in their own right. A worsening headache, repeated vomiting or new neurological symptoms after a head injury should prompt assessment by a GP or other appropriate healthcare professional. The aim throughout is to find evidence that actually matches the symptoms.

What Can Be Done If A Minor Head Injury Has Affected My Binocular Vision?

Treatment depends on which part of your binocular vision has been affected and what we find during your assessment. There’s no single approach that applies to every case.

• Prescription lenses or prism — considered where the main difficulty involves eye alignment or focusing effort. Prism changes where an image appears to be, which can alter the alignment effort required from the eyes. Results vary, and haven’t yet been confirmed in larger studies.
• Structured vision therapy — considered where convergence problems are identified after concussion. The available evidence is strongest for structured therapy addressing convergence problems after concussion.

Alongside any of these, we may also discuss practical changes to reading, screen work and other visually demanding activities, to make them more manageable while symptoms are being investigated.

Most importantly, persistent visual symptoms following a head injury deserve a proper assessment rather than assumptions about their cause. Treatment starts with identifying the actual problem.

Final Thoughts

Visual symptoms can sometimes become noticeable after a bump that seemed minor at the time, even after the bruise has faded and the incident itself has been forgotten. If you’ve noticed persistent visual symptoms since a head injury, you can book an assessment with us at Harmony Vision Care on the Gold Coast.

To arrange an appointment simply give us a call at (07) 5520 5900, and our friendly staff will be happy to assist you in booking a convenient time for your consultation. Alternatively, you can click the “BOOK AN APPOINTMENT” button on our website to schedule a time by yourself.