Does viewing text through yellow or blue filters help dyslexic children to learn to read?

The Effect of Yellow and Blue lenses on Reading and Spelling Skills

Status

Active, not recruiting

Phases

Phase 3

Study type

Interventional

Source

ISRCTN

Registry ID

ISRCTN39964318

Enrollment

200

Registered

2018-03-02

Start date

2016-09-01

Completion date

Unknown

Last updated

2025-11-24

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

Conditions

Children's visual reading problems (dyslexia) Signs and Symptoms Dyslexia

Interventions

Based on their visual symptoms, participants are allocated to a blue filter group or yellow filter group. Then, selected at random, the ‘blues’ are asked to wear either blue or placebo grey filters fo

Eligibility

Sex/Gender

All

Age

7 Years to 11 Years

Inclusion criteria

Inclusion criteria: 1. Children with visual reading problems 2. Age 7-11 3. Male and female

Exclusion criteria

Exclusion criteria: Current key exclusion criteria as of 13/11/2025: 1. v. low intelligence 2. Any medical or neurological diagnosis _____ Previous key exclusion criteria: 1. English not first language 2. Any medical or neurological diagnosis

Design outcomes

Primary

Measure	Time frame
Single word reading progress is measured using BAS reading and spelling at baseline, 3, 6 and 9 months Visual reading symptoms are measured using visual symptoms questionnaire at baseline, 3, 6 and 9 months	—

Secondary

Measure	Time frame
Optometric status is measured using standard optometric tests at baseline, 3 months, 6 months and 9 months	—

Countries

England, United Kingdom

Contacts

Public ContactJohn Stein

john.stein@dpag.ox.ac.uk+44(0) 1865 272552

Outcome results

None listed

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