Prevalence Study

Study Aims

This study aimed to find out approximately how many children may be affected by CVI and what is the best way of identifying who might be at risk.

The study involved:

  1. Recruiting mainstream primary schools in Gloucester, Southampton and North Somerset.
  2. Collecting school based information on children, including ethnicity, known diagnoses and any additional needs.
  3. Collecting teacher report data on a brief standard 25 item questionnaire about each child in their classes in years 1-6
  4. Collecting parent report data on a 6-10 item survey about their child/ren in years 1-6
  5.  Conducting nested detailed assessments of approximately 10% of children in a ‘Looking Activities’ session on school premises (with parental consent), led by a specialist vision researcher

Feedback for schools

Following the analysis of all the data, we visited our participating schools with as much information as possible. We told the schools about particular children in their school who seemed to struggle with the vision tests in a way that suggests CVI.


Study Results

We have published a paper with the overall study results in the journal ‘Developmental Medicine & Child Neurology’. Here is a direct link to the paper: Prevalence Paper


Here is a link to a Worldwide Webinar from the World Society of Paediatric Ophthalmology and Strabismus, where our very own Cathy Williams talks about our study and the results: WSPOS Webinar on CVI


For more information on CVI, there are two main organisations in the UK who aim to raise awareness and understanding of CVI:

The CVI Society:

CVI Scotland: