Interventions & approaches

Coloured overlays

Also known as: Tinted overlays, Coloured filters, Tinted lenses, Irlen lenses, Visual stress overlays

Written by Sarah Iqbal, Specialist Teacher / Qualified Teacher of Vision Impairment (QTVI, MA SEN, AMBDA)

Definition

Coloured overlays are tinted sheets placed over text for claimed “visual stress”; a 2016 independent review found no reliable reading benefit, and UK optometry guidance says they do not treat dyslexia.

In context for parents

Key checkpoints

  • Coloured overlays are tinted acetate sheets, usually A4 or reading-ruler sized, laid over a page; precision-tinted lenses are a related prescription product.
  • Visual stress, also called Meares-Irlen syndrome, describes reported glare, blur or movement of print; it is not dyslexia (College of Optometrists guidance, accessed 2026).
  • Griffiths, Taylor, Henderson and Barrett's 2016 systematic review found smaller effects in better-designed studies and did not support overlays or lenses as a reading intervention.
  • Ritchie, Della Sala and McIntosh's 2011 double-masked randomised trial found no immediate reading benefit from Irlen overlays for children with reading difficulties.
  • Claims that 20% of dyslexic readers, or 10% of everyone, need a colour lack sound evidence; children may choose a different colour when retested.
  • A coloured overlay must not replace structured teaching for a child's phonological decoding difficulty.

In classrooms, I meet children who say the page glares, the lines swim or black print seems to move. An overlay is a tinted acetate sheet placed over that page. Some children say a chosen colour feels more comfortable. That report deserves listening to, but it is not proof that reading accuracy or fluency has improved.

The distinction from dyslexia is crucial. Dyslexia is a phonological difficulty, not a visual one. The College of Optometrists says most people with dyslexia do not have visual stress and warns against claiming that tinted overlays or lenses treat specific learning difficulties. “Irlen syndrome” is not an NHS-recognised diagnosis.

Evidence for overlays remains weak and contested. Evans and Allen's 2016 proponent review argued that controlled trials support an effect for Intuitive Overlays. Griffiths and colleagues' independent 2016 review found that effects became smaller as study quality improved. A double-masked randomised trial by Ritchie and colleagues in 2011 found no immediate reading benefit. Those null results matter when a school is deciding what to provide.

When a child reports print distortion, I advise parents to begin with a standard NHS-funded eye test. Ordinary uncorrected vision problems can account for many complaints. An inexpensive overlay may then be tried as a comfort aid, with the child's response recorded and reviewed. It should never consume the year in which structured reading teaching should have happened.

Related terms

The terms parents most often see alongside Coloured overlays.

Where parents ask about this

A blue reading ruler comes home in the book bag, perhaps followed by a private recommendation for tinted lenses costing hundreds of pounds. Parents understandably search “school gave my child a coloured overlay”, “coloured overlays dyslexia do they work”, “visual stress test child”, “Irlen syndrome NHS” and “tinted glasses for reading child”. Before deciding whether this is a diagnosis, comfort measure or reading intervention, ask what difficulty the colour is meant to address and whether structured decoding teaching continues. A standard NHS-funded eye test should come first when a child reports print distortion or discomfort. With the reports and classroom evidence in view, a Beaakon specialist helps separate visual comfort from dyslexia provision and frame a request for school support that addresses the child's actual reading needs without allowing an overlay to displace reading teaching.

References

The primary legislation, statutory guidance, research, and clinical tools this page draws on.