Q: I don’t live in the Newcastle area; can I still take part/find out about the results of your research?

A: If you are willing to travel to Newcastle University to take part, then yes, please fill in our form.

Please note that for the first stage of this project (screening of male relatives), we are not able to reimburse costs for travel or time. However, for the second stage, we will be able to provide a contribution towards this.

If you are not able to take part, but would still like to find out about our results, please keep an eye on this website, which we will keep updated with results and publications.

Q: Am I a potential tetrachromat?

A: The best way to identify potential tetrachromats is by looking at maternal male relatives. From our research so far, we know that the most likely candidates for tetrachromacy are those who carry the gene for very mild colour vision deficiency. This means that their son/father/ maternal uncle/maternal grandfather etc. will be very slightly colour blind.

From past research we know that tetrachromats can detect and discriminate between colours that normal people cannot see. However, as we don't have access to people's personal experiences we are unable to label or describe these perceptions.

Q: Is there an online test that I can do?

A: Unfortunately, computer screens do not provide enough colour information to be able to ‘tap into’ the extra dimension that tetrachromats may possess. It is therefore impossible for an online test to investigate tetrachromacy.

Q: How do I know if my son/father/other male relative has a mild colour deficiency?

A: There are several ways in which you might know about your male relative's colour vision. The most common is that he will have a diagnosis from the optician or school health visitor. However, as we are looking for very mild colour deficiencies, some people may be able to pass the diagnostic tests despite their colour deficiency.

We are particularly looking for males who think they may see colours differently, but have not been able to obtain a difinitive diagnosis from an optician.

Q: Is there an online test that my son/other male relative can do to find out if he is colour deficient?

A: The x-rite test (found here) may give you an idea about his colour vision, however, the colours produced by computer screens vary considerably and therefore these types of test are not completely reliable.

Q: I see colour differently with each eye, what does this mean?

A: Some women who carry the gene for colour blindness may see colour differently with each eye. This is due to a process knows as random X-inactivation.

These women have one X chromosome with the normal colour vision gene (inherited from one parent) and one X chromosome with the colour blind gene (inherited from their other parent).

Random X-inactivation causes some of the cells in the retina to use the normal gene from one X chromosome and others to use the colour blind gene from the other X chromosome. As this process is random, sometimes one eye gets more than its fair share from one X chromosome, leading to slightly different colour vision in each eye.