cuddly toys sitting atop an acuity test board

We supported Dr Pete Jones’s research to demonstrate that children can test their own vision using child friendly tests, independently and with repeatable results. The next phase of this study is to issue these tests to young people for home use.

Home monitoring of vision

Since the COVID-19 pandemic, the interest in home vision testing increased. 

Remote consultations are seen as more convenient and cut travel and waiting time often experienced in hospital eye appointments. 

Remote assessment of vision can be particularly helpful for children and young people. It can reduce time away from school and parental time away from work or caring responsibilities. 

This is especially relevant for children undergoing amblyopia treatment (also known as lazy eye), who may have to have their vision checked every 8 – 12 weeks. 


Learn more
  • Amblyopia develops in childhood and results in reduced vision in one eye.
  • It occurs when one eye is used less than the other from birth to seven years of age which leads to the brain preferring the better eye.
  • It can be caused by strabismus (also known as squint) which causes a turn in one eye; difference in glasses prescription between the two eyes; an obstacle blocking visual stimulation to the eye, for example droopy eye lid or cataract.
  • Prescription glasses and patching of the good eye to stimulate the weaker eye are the main treatments.

Visual acuity and contrast sensitivity function

Visual acuity, which is how clearly we can see and distinguish small details with precision at a distance, is the main clinical assessment of vision. 

Home monitoring of visual acuity in children has been successfully tested using printed tests, phone apps and web-based systems. 

For children with amblyopia and other vision impairments, assessment of contrast sensitivity function (CSF) is a more relevant and informing test.

Contrast sensitivity function is a fundamental aspect of vision, which determines the threshold between the seen and the unseen.

Dr Pete Jones, lecturer in optometry and visual science at City, University of London, and honorary senior research fellow at UCL Institute of Ophthalmology

CSF is the ability to perceive sharp and clear outlines of very small objects, and identify minute differences in the shadings and patterns. It allows us to distinguish objects without a clear outline from their background. 

CSF is important in performing everyday tasks as diverse as reading, writing, recognising faces, telling the time on a clock, walking, balancing, pouring liquids and using kitchen utensils. 

Using fun and engaging, child-friendly games as a possibility for monitoring paediatric eye conditions at home

In children with amblyopia CSF is reduced, even after treatment has restored visual acuity to normal levels.

In those with vision impairment, CSF has been shown to better predict visual function and disease progression.

Despite its relevance in the detection and monitoring of amblyopia, home testing of contrast sensitivity in children has not been previously assessed.

Child friendly vision tests

In this study funded through our springboard award, Dr Jones and team have shown that children are able to measure their CSF using tablet-or paper-based tests.

Forty children, aged 5–15 years, with amblyopia (10 children), other vision impairment (10 children) or good vision (20 children) measured their own vision using three distinct CSF tests: Manifolds optotype test, PopCSF gamified test, and Spotchecks paper based test.

Child friendly CSF tests

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Manifold, screen based optotype test

  • This test was applied through a tablet Manifold Home Monitor app with Sloan optotypes, which are specifically formatted letters used in standard clinical eye charts.
  • Thirty filtered Sloan letters were presented sequentially, with varying contrast and spatial frequency.
  • Participants had to identify each letter by touching the corresponding letter on a response screen.
  • The Manifold test has been used in adults with myopia, multiple sclerosis and retinal vein occlusion, as well as in adolescents with amblyopia.

PopCSF, a gamified vision test

  • This test is a tablet-based game where players have to pop’ moving bubbles (Gabor patches) by touching them as they appeared randomly around the screen.
  • The spatial frequency and contrast of each stimulus varied adaptively.
  • The test was designed to be engaging and fun for children to use and it measured CSF across the visual field as the targets drifted around the entire screen.

Spotchecks, a paper-based test

  • This is a pen-and-paper-based, single-use contrast sensitivity test.
  • Each test consists of a single sheet of A4 paper containing a grid of 120 boxes, each containing a grey spot of varying contrast in one of five locations. Participants were asked to mark the target in each box.
  • The test gives a summary measure of contrast sensitivity similar to that provided by the Pelli–Robson contrast sensitivity chart applied in a clinical setting.

Children performed the tests in a laboratory with minimal supervision. Children with good vision or amblyopia did all three tests with one eye at a time, with the fellow eye patched. 

Completion rate, test repeatability, duration and participants’ preferences were recorded for each test. Test times were 2–4 min per eye.

Summary of key findings

  • All tests correlated with clinical measurements of visual acuity and contrast sensitivity.
  • All tests differentiated between children with reduced contrast sensitivity and control participants.
  • PopCSF and Spotchecks were able to differentiate between children with amblyopia and those with good vision.
  • The PopCSF test can correctly identify moderately amblyopic eyes from fellow eyes.
  • The most reliable test was Spotchecks, the quickest was PopCSF and participants’ favourite was PopCSF.
  • Nearly all participants said they would be willing to use at least one of these tests at home.


of children said they would measure their own vision at home using at least one of these tests

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preferred the PopCSF test and said they could perform it daily

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preferred Spotchecks and said they could perform it weekly

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preferred Manifold and said they could perform it weekly


Measuring visual acuity provides a quick and informative test of visual function in the clinic. 

For home use, where test duration is not limited by clinician time, the findings of this study suggest using the more detailed assessment of visual function offered by contrast sensitivity testing. 

This is particularly relevant in children receiving treatment for amblyopia and those with other vision impairments.

Young children with and without eye disease were able to test their CSF with minimal supervision and repeatable results, which provides proof of concept for performing these tests at home. 

The next phase of this study is to try out these tests in a home setting, which will enable the researchers to compare CSF measurements from the laboratory to those obtained at home.

Dr Pete Jones presents to Young People Advisory Group (YPAG)

Promoting experts and impact

Our springboard awards are designed to help researchers develop new ideas and take the next step in their academic careers.

This springboard award and nation- and worldwide collaborations were instrumental in Dr Pete Jones obtaining a permanent lectureship at City, University of London, where he currently teaches biology of the eye to around 250 new and aspiring optometrists and nurses every year.

This appointment is Dr Jones’s first permanent faculty position and made him eligible to supervise PhD students and apply for external grant funding. 

Since 2021 he has supervised 3 PhD students, and successfully raised £500,000 in grant funding towards the continuing development and validation of new, portable, child-friendly vision tests for use in and outside of conventional eye care facilities.

None of this work would have taken place without Moorfields Eye Charity springboard grant.

Dr Pete Jones

The novel vision-testing technologies developed during this springboard grant are now vital tools, trialled worldwide as a way of providing ongoing vision monitoring in a number of settings.

The convenience of these self-administered tests means that they can also be deployed in clinics, as means of better using patients’ time and improving patients’ experience. 

Planned applications for the vision tests:

  • Moorfields site at Bedford Hospital - for collection of additional vision data from patients while they wait for routine hospital appointments
  • Moorfields Eye Hospital - for assessment of young children undergoing pioneering gene therapies
  • Oxford University – pilot study under way to assess older children receiving new treatments for amblyopia
  • Singapore Eye Research Institute – pilot study under way to assess adults with glaucoma trialling a new form of neuroprotective food supplement