Vision & Voice: Why Functional Vision Assessment Is Essential for Effective Communication

Krish Zlotin
Mar 31
4 min read

Updated: Apr 1

Imagine trying to select a symbol...

but it’s hard to find and even harder to accurately reach - like playing whack-a-mole.

That's how frustrating it can be for someone struggling with vision processing.

Vision is not just about eyesight. It’s about how the brain processes visual information.

And when that processing is inefficient, inconsistent, or overwhelmed—communication becomes harder than it needs to be.

Communication Support Starts with Access

When supporting someone to communicate, we often focus on what they want to say and how they can say it.

But there’s a crucial question that is often missed:

Can they actually see the communication system we’re giving them?

Many of the communication supports we use every day are fundamentally visual, including:

AAC devices and communication apps
PODD books and communication boards
Visual schedules and routine supports
Choice boards and early communication visuals

To use any visual communication system, a person needs to first find what they’re looking for, focus on it long enough to understand it, and then act on it.

If any part of this visual process breaks down, communication becomes difficult—regardless of language ability.

What we might interpret as:

❌“They’re not engaging”

❌“They’re not ready”

❌“They don’t understand”

…may actually be:

👉 They can’t reliably see or process what’s in front of them.

It’s Not Static — Vision Can Fluctuate

Vision is often not consistent - this applies to EVERYONE of all abilities.

Vision fluctuates based on:

However, the threshold for those with neurological presentations can be significantly different.

Have you ever turned down the music when trying to park your car?

Or found yourself re-reading the same recipe over and over again as you cook in a busy kitchen while juggling young children?

In those moments, it’s not that you don’t know what to do.

It’s that your brain is working harder to filter, organise, and focus.

Now imagine that effort isn’t occasional—but constant.

Constant effort required - to use a device, coordinate movement, and filter through competing input just to focus on seeing and understanding what's in front of you.

And when that level of effort is required just to process what’s seen—communication becomes slower, less accurate, and far more exhausting.

Noise - just normal everyday noise ... footsteps, 2 people talking, neighbours dog barking, cars driving past, someone mowing their lawn, music playing in the background..can be overwhelming to the point of where a person is unable to focus on what's in front of them.

Parking the car might happen twice a day - where you really need to concentrate visually and be extra aware of your surroundings. But for someone with neurological differences, this situation could be happening every time they want to communicate, every time there is a change in routine, with every new person they meet, during therapy sessions where they are constantly pushed outside their comfort zone to learn new skills.

Someone might make clear progress in a quiet, one-on-one therapy session, especially where a consistent routine is followed.

They can find symbols, make selections, and engage with the system.

But place that same person in a busy home environment—with siblings running around, pets, bright open spaces, noise, glare—

…and everything changes.

Suddenly:

❌Symbols are harder to find

❌Attention drops

❌Accuracy decreases

❌Engagement fades

Not because they’ve “lost the skill”. Not because the person doesn’t understand. Not because they aren’t trying.

👉 but because the visual demands of the environment have changed.

If we don’t account for this, we risk designing systems that only work in ideal conditions—not in real life.

And communication isn't just for ideal conditions.

It needs to happen in everyday life - messy, dynamic, unpredictable environments.

Read more on Functional Vision - What It Means to SEE here.

Vision Before Voice:

Setting Communication Up for Success

When functional vision is considered early, communication supports can be tailored to the individual.

This might include:

Simplifying layouts and reducing clutter
Increasing spacing and target size
Using high-contrast or meaningful visuals
Positioning materials within the optimal visual field
Adjusting lighting and the surrounding environment
Allowing for variability and fatigue
Incorporating auditory or tactile feedback—especially for individuals who rely more on these senses

But it’s not just about what we change.

It’s about understanding how a person experiences and interprets their visual world—and how that changes across environments.

Why Collaboration Matters

This is where collaboration between speech pathologists and orthoptists becomes essential.

Speech pathologists understand communication and language. Orthoptists understand how vision functions in real-world contexts.

Together, they bring both sides of the picture.

Because this isn’t just about seeing.

It’s about visual access.

❓Can the person look at the system?

❓For how long can they sustain that look?

❓How quickly can they recognise what they see?

❓Can they accurately guide their reach or gaze to the target?

Together, they can answer:

👉 What does this person want to communicate?

👉 How can they best access communication visually?

This collaboration leads to:

✅More accessible communication systems

✅Better assessment and decision-making

✅Reduced trial-and-error

✅Stronger outcomes for individuals and families

The Bottom Line

Communication is not just about having a voice—it’s about having access to that voice.

Across all ages and communication methods, vision plays a critical role in that access.

Before introducing or progressing any communication support, we need to ask:

❓Can this person access it visually well enough to use it?

Because when vision and voice work together—communication doesn’t just improve…

it becomes possible.

the seeing brain