The visual dyslexia myth is costing you the wrong adjustments

In October 2025, the International Dyslexia Association revised its definition of dyslexia for the first time since 2002. The revision drew on 23 years of neuroimaging research and expert input from researchers, clinicians, and dyslexic adults across the world. Phonological processing was still at the centre.

It's always been at the centre. And yet the most common thing a newly identified dyslexic adult hears is that their condition is about seeing letters backwards.

If you've accepted that framing, you may have spent years looking for a visual solution to a problem that isn't primarily visual. This article explains what dyslexia research actually says, and what it means for the adjustments you should be asking for at work.

Where the reversal story came from

Letter reversals do happen. Children learning to read often write b as d, and p as q. Dyslexic children take longer to stop doing it than their peers, which is real and well-documented.

The reversals are visible, memorable, and easy to describe to a parent or teacher. So the story that spread through schools, workplaces, and HR materials was that dyslexic people see letters in the wrong orientation.

A 2025 peer-reviewed study on letter mirror-image processing in dyslexic adults confirmed that these effects do persist into adulthood for some dyslexic readers. But the researchers were careful about scope: these effects are a secondary feature of how the reading system develops, with phonological processing remaining the primary, most-replicated cognitive mechanism. Describing a symptom is different from identifying the mechanism. And the mechanism is what determines which adjustments will actually move the needle.

If your employer's understanding of dyslexia starts and ends with letter reversals, the adjustment plan they've built is probably solving the wrong problem.

What phonological processing actually means

Reading requires two things.

The first is recognising written shapes: the letter A, the word "communicate" on a page. Most dyslexic adults can do this without difficulty. The eye sees the word. That part works.

The second is connecting those shapes to sounds: the phoneme sequence that corresponds to the written pattern. This is phonological processing. And this is where the difficulty lies for the majority of dyslexic adults.

The mapping is slower. Under time pressure, it breaks down faster. Unfamiliar words are harder because there's no well-worn path yet between the shape and the sound. Re-reading something three times helps precisely because repeated exposure strengthens the mapping. When you read a dense document and retain very little of it, your processing capacity has been used up on decoding, leaving less for comprehension. That's the mechanism.

The IDA's 2025 revised definition (International Dyslexia Association, October 2025) names phonological and morphological processing difficulties as the common, evidence-backed features. The revision is more nuanced than the 2002 version, acknowledging that presentation varies across individuals and writing systems. But phonological processing is still the mechanism with the deepest research base behind it.

Your difficulty with reading emails quickly, drafting responses under time pressure, or following a document in a meeting is a processing speed problem, not a visual one. That distinction is specific, documentable, and directly relevant to which adjustments will help.

What the myth costs you at work

An employer who understands dyslexia as a visual problem will offer visual solutions. A pastel background on your screen. A coloured overlay. A font change to OpenDyslexic.

These can feel like support. For some dyslexic employees, they provide minor relief from visual fatigue during long reading sessions, which is real. But the College of Optometrists is explicit on what the evidence actually shows: there is "not yet a reliable evidence base on which to recommend coloured overlays or lenses for the alleviation of reading difficulty" (College of Optometrists clinical guidance, updated 2024). A 2016 peer-reviewed systematic review of controlled trials on coloured overlays found the majority of studies at high risk of bias.

When overlays are the headline adjustment and nothing else changes, the phonological processing demand stays exactly the same. You're still re-reading the email five times before you send it. You're still taking twice as long to process a meeting brief as your non-dyslexic colleague sitting three desks away. You're still spending unpaid cognitive effort on tasks that others breeze through.

If you want to put a number on that daily cost: the masking cost calculator converts your salary and your daily workarounds into an annual figure. Most dyslexic employees find the result higher than they expected.

A dyslexia adjustment plan built mainly around visual tools is worth revisiting. Bring a specific question to your next review: what supports exist for processing time, preparation, and reading speed?

The adjustments that target the actual problem

Four categories of adjustment have direct links to phonological processing needs. All of them can be requested as reasonable adjustments under the Equality Act 2010 (UK) or the ADA (US).

Extra processing time. For reading documents, drafting written responses, and reviewing materials before a meeting. A reasonable adjustment can specify that you receive documents at least 24 hours before any meeting requiring you to have read them. This costs your employer almost nothing and addresses a documented need precisely.

Written versions of verbal instructions. Spoken information requires holding phoneme sequences in working memory while simultaneously processing meaning. A follow-up email or written action list after verbal conversations removes this demand entirely. It's one of the lowest-cost adjustments available, and consistently one of the most useful for dyslexic employees in knowledge-work roles.

Text-to-speech access. Microsoft Immersive Reader is built into M365 at no extra cost, and it works across Word, Teams meeting transcripts, and OneNote. For PDFs and other formats, Speechify's free tier covers most daily use cases. Both convert written text to audio, removing the phonological mapping step for information-intake tasks.

Preparation time before meetings. Protected time, without other demands competing for attention, to read an agenda and any supporting documents at your own pace. Processing material in advance means the meeting itself can be used for comprehension and contribution rather than decoding. This is different from just receiving documents early: it means the time to actually read them without interruption.

If you want to formalise any of these as a written adjustment request, the reasonable adjustments builder turns your specific working challenges into a conversation plan and a draft email in about two minutes.

If your current adjustment plan doesn't include at least one item from each of these categories, it's targeting the symptom layer rather than the mechanism.

The call — what to do if your adjustments aren't working

If your plan consists mainly of font choices, coloured backgrounds, and a line in your HR file, it's worth asking for a formal review.

UK employers have a continuing duty to make reasonable adjustments under the Equality Act 2010. The duty doesn't expire after the first adjustment conversation. If existing adjustments aren't delivering practical support, you can request a review in writing. US employers carry the same obligation under the ADA's interactive process: the conversation can be reopened at any time.

State specifically what you need. Processing time, written instruction formats, text-to-speech access, preparation windows before meetings. These are concrete requests with a direct evidence basis. Name the mechanism and name the adjustment. That combination gives HR something specific to respond to.

If you haven't had a formal workplace needs assessment, one is worth considering. A proper assessment will test phonological processing, working memory, and reading speed, and it produces a written report your employer can act on. UK assessments currently cost between £350 and £882 depending on the assessor (British Dyslexia Association, June 2026). Access to Work can cover the full cost. Nine in 10 dyslexic employees eligible for Access to Work funding have never applied (British Dyslexia Association, January 2024). The Access to Work calculator shows what you're likely to qualify for.

Coloured overlays don't feature prominently in a proper clinical workplace assessment report. The four categories above do, because the evidence points there.

If your current adjustments aren't reducing the daily load, a written request to review the plan, naming the phonological processing adjustments you need, is both within your rights and entirely reasonable for most employers to provide.