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

INTERVENTION: 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 for 3 months , then all switch to blue. Likewise the ‘yellows’ are randomised to yellow or placebo grey, then all switch to yellow after 3 months. Participants use their filter when reading, and are followed up with psychometric and visual assessments at 3, 6 and 9 months. CONDITION: Children's visual reading problems (dyslexia) ; Signs and Symptoms ; Dyslexia PRIMARY OUTCOME: ; 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 OUTCOME: Optometric status is measured using standard optometric tests at baseline, 3 months, 6 months and 9 months INCLUSION CRITERIA: 1. Children with visual reading problems 2. Age 7‐11 3. Male and female