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Colour blindness can impact learning across the curriculum and can be a serious disadvantage in some subjects.

Our studies show that by Year 7 about 80% of children have never been screened for colour blindness, despite 75% having had an NHS eye test. This means there will be a significant number of colour blind students in every secondary school who will not even be aware that they are colour blind. Consequently neither you/your school or the child’s parents/other teachers will know which pupils are affected. As a consequence non-diagnosed pupils are unlikely to receive any support at all.

As a teacher you are unlikely to have had any training in how to identify and support your colour blind students and you may not be aware that these students are entitled to extra help in some external exams (for example geography, chemistry practicals). For more specific advice on impacts for external exams see The WJEC/Eduqas CVD Guide which, although created for those designing questions for external assessments, is applicable to many classroom circumstances. By adopting the advice and techniques relevant to your subject you can ensure that all of your colour blind learners including the undiagnosed ones, are better supported in your lessons. See also the Secondary School and Further Education section of our Resources for Teachers.

Take particular care with interactive whiteboards and information projected onto screens as these can ‘wash out’ colours making coloured information more difficult to see. Colour blind students can even miss important parts of the lessons because they can’t clearly see the pointer (read the comments of International Scotland rugby players Mike Blair and Chris Paterson discuss this in the ‘World Rugby’ guidance – scroll down to Post Match Analysis,  Classroom Training and Education) or because of poor choice of colours chosen to highlight graphs, charts and diagrams.

science class

Normal Vision

science class - Deuteranopia


Please don’t assume pupils will let you know if they are having difficulties. Even CEOs of large international businesses don’t speak up if they can’t understand presentations or even their own company reports!

world map

Normal Vision

world map - protanopia


Imagine studying GCSE Geography and being faced with questions in your mock exam paper  when to you the world vector map appears like the Protanopia version of the world vector map above where so many colours appear to be the same. This is exactly the situation facing thousands of colour blind students using everyday school resources as well as exam papers, so it’s easy to understand how unsupported colour blind students are likely to be negatively impacted in learning across most subjects due to the huge number of inaccessible resources, including online resources and websites in general.

The main problem subjects are maths, all areas of science, geography, sport and art but some aspects of other subjects, such as languages and media studies, can also cause issues. Any situation which requires a colour blind learner to understand information based on colour only is likely to be at best a challenge and at worst an impossibility for them.

Maps, graphs and charts are widely used in many different subjects but can be extraordinarily difficult for colour blind students to interpret. They will frequently miss important information unless maps/graphs/charts etc. are also fully labelled using text, symbols or patterns.


There are numerous areas of the science curriculum where colour blind students will experience difficulties in understanding what is being taught due to colour issues. Some examples of the challenges are

  • misreading litmus paper, universal and other indicators
  • inability to distinguish between different chemical solutions by colour, including colour changes in chemical titrations
  • inability to identify metals by the colour of the flame produced when the metal is burnt
  • inability to accurately read stained slides under a microscope
  • inability to accurately distinguish information during dissections in biology
  • inability to identify species of plants or insects correctly where important information relies upon correct colour discrimination
  • difficulty fully understanding coloured diagrams in textbooks and online resources, particularly in biology
  • difficulty with coloured wiring, use of prisms in physics
  • difficulty in understanding teaching of, with and about light

NOTE: Access Arrangements – some Examination bodies do not allow a colour ‘reader’ in some practicals for colour blind students. Check the rules which apply to your school’s examining body before entering a colour blind student for external examinations (see External Exams below).


Difficulties in sporting situations are covered in much more detail in our Sport section, where you can download factsheets and advice documents and watch videos. Most issues are relatively easy to avoid or rectify providing the teacher is aware of the challenges for colour blind athletes and players.

indoor football

Normal Vision

indoor football - deuteranopia


External Exams

Colour Blind Awareness is a member of Ofqual’s Access Consultation Forum. Ofqual is addressing colour blindness accessibility issues including with the JCQ but expect some confusion still from some exam boards in what help can be provided. Some Assessment Organisations (e.g. WJEC/Edquas above) have designed colour blindness challenges out of their assessments, others offer accessible papers only to diagnosed candidates and some have not yet fully addresses the issue of colour blindness accessibility and rely on Access Arrangements. JCQ Access Arrangements are on the whole unsuitable for colour blind students. Please also contact us/or ask your SENco or exam officers if you are unsure. At present undiagnosed students will not be able to access any support at all for eternal exams and we are working to change this situation as a matter of urgency. Ofqual has recently (Spring 2022) consulted on some changes as part of it’s Consultation on Designing and Developing Accessible Assessments.


Careers and Vocational Courses

Colour blind students about to make choices regarding their future careers and vocational courses must be properly advised on careers which they will find it difficult or impossible to pursue.

Most people know that a colour blind person is unlikely to be able to become a pilot but there are many other careers which are unsuitable for colour blind people and numerous jobs where the colour blind will find it difficult to function as well as their colour normal colleagues.

The most common industries where colour blind people are likely to be excluded are those where colour vision is critical to safety especially where coloured lights are used and a mistake could lead to a fatality. Most transport industries exclude colour blind people from most roles as do most uniformed services and a large number of disciplines in the Armed Forces.

Click here for a downloadable copy of a document which has been prepared by the Australian Colour Bind Awareness and Support Group and provides a useful summary of careers which will be affected by colour vision deficiency and includes some like medicine, which would not be immediately obvious to someone with normal colour vision.