The effect of wearing yellow or blue filters on reading and spelling ability

The effect of wearing yellow or blue filters on reading and spelling ability: a randomised controlled trial

Status

Recruiting

Phases

Unknown

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN46126947

Enrollment

200

Registered

2015-05-08

Start date

2014-10-30

Completion date

Unknown

Last updated

2020-06-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Backward reading (dyslexia) Not Applicable

Interventions

Viewing text through yellow, blue or placebo grey filters

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Children experiencing reading difficulties

Exclusion criteria

Exclusion criteria: 1. Not fluent in English 2. Any diagnosed medical condition

Design outcomes

Primary

Measure	Time frame
Reading and spelling changes To be assessed at 3, 6 and 9 months	—

Secondary

Measure	Time frame
1. BAS matrices 2. Recall of digits 3. Similarities changes 4. Visual symptom changes 5. Random dot motion sensitivity changes To be assessed at 3, 6 and 9 months	—

Countries

United Kingdom

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026