However, they don't know do not know why this is and said more research is needed.
Data was used from a database of more than 10,000 individuals, mostly African Americans and European Americans, diagnosed with at least one psychiatric illness.
Many have multiple diagnoses of diseases, including depression, schizophrenia and bipolar disorder, as well as addiction and alcohol or drug dependence.
They filtered out the alcohol-dependent patients with European ancestry, and found a total of 1,263.
After noticing the connection between eye colour and alcoholism, they retested their analysis three times.
They arranged and rearranged the groups to compare age, gender and different ethnic or geographic backgrounds, such as southern and northern parts of the continent.
But the connection between a lighter eye colour and an addiction to alcohol was still strong.
The paper was published in the July issue of the American Journal of Medical Genetics: Neuropsychiatric Genetics.
- nzherald.co.nz, Daily Mail