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

Plain English summary of protocol

Background and study aims
Up to half of all children with reading problems find it difficult to see text clearly. Letters appear to blur, glare, go double or move around, and these problems can give them headaches. Previous research has shown that these problems may be due to the poor readers having reduced sensitivity to time varying low−level visual stimuli, for example, moving dots. This sensitivity is important for making visual targets appear stationary despite eye movements and it is controlled by a system of large specialised (magnocellular) neurones in the brain. The development of these neurones have been found to be impaired in many children with reading problems. There are good physiological reasons for supposing that viewing text through either simple blue or yellow coloured filters may improve magnocellular function. We have found that indeed this is so, and that the use of these filters is often followed by rapid reading and spelling progress. However, these claims have been disputed. There is no agreement about whether coloured filters can really help more than a placebo. Here, we will test if simple and cheap blue or yellow filters can really help children with reading difficulties. If so, this low cost technique should be used wherever appropriate, in order to help the 10−20% of primary school children who have great difficulties learning to read.

Who can participate?
Children experiencing reading difficulties

What does the study involve?
The carers of all potential participants attending Dyslexia Research Trust (DRT) clinics are asked to allow their child to take part in the research. The only difference from the routine assessments carried out in the clinics is that each child is treated with blue, grey and then yellow filters in a random order. Upon arrival at the DRT, we discuss the study with them, ensure that both the child and carer understand why we are doing the study, what we hope to find, what will be expected of them and ask them to sign a consent form. Psychometric assessments (pen and paper tests) are carried out along with a visual assessment, clinical tests of vision and recordings of the movement of eyes. Following completion of these tests each child is given an envelope containing either yellow, grey or blue filters. This envelope is not to be opened until they leave the clinic to ensure that the researchers do not know which colour the child received. At a second appointment after 3 months, the filters will be swapped to another colour. The researchers will be blind to the colour the child receives at any of the follow ups. To assess the effects of the yellow, grey and blue lenses the children are further assessed at 3, 6 and 9 months when all the psychometric and visual assessments are retested. We ask the participants not to disclose the colour of the filter they have received to the researchers . Only at the end of the fourth and final assessment are researchers told treatment order, once the participant has finished the study.

What are the possible benefits and risks of participating?
None of the colours are likely to harm the children in any way and the reading of the majority of them is likely to be helped by one or another colour.

Where is the study run from?
The Dyslexia Research Trust clinic (Reading)

When is the study starting and how long is it expected to run for?
October 2014 to October 2022

Who is funding the study?
Dyslexia Research Trust (UK)

Who is the main contact?
Professor John Stein
john.stein@dpag.ox.ac.uk

Contact information

Study information

Eligibility

Locations

Countries of recruitment

• England
• United Kingdom

Study participating centre

Sponsor information

University of Oxford
University/education

Wellington Sq
Oxford
OX1 2JD
England
United Kingdom

Phone	44-1865-270014
Email	admin@ox.ac.uk
Website	http://www.ox.ac.uk/
"ROR"	https://ror.org/052gg0110

Funders

Funder type

Not defined

Results and Publications

Editorial Notes

12/06/2020: The following changes were made to the trial record:
1. The overall end date was changed from 28/10/2019 to 28/10/2022.
2. The intention to publish date was added.
3. The plain English summary was updated to reflect these changes.
23/01/2020: Internal review.