eCite Digital Repository

Donít it make your brown eyes blue? A comparison of iris colour across latitude in Australian twins


Sanfilippo, PG and Wilkinson, CH and Ruddle, JB and Zhu, G and Martin, NG and Hewitt, AW and Mackey, DA, Don't it make your brown eyes blue? A comparison of iris colour across latitude in Australian twins, Clinical and Experimental Optometry, 98, (2) pp. 172-176. ISSN 0816-4622 (2015) [Refereed Article]

Copyright Statement

Copyright 2014 Optometry Australia

DOI: doi:10.1111/cxo.12209


Background: The aim was to determine whether latitudinal (Queensland versus Tasmania) variation in reported disease frequency in Australia may be biased by differences in population.

Methods: A retrospective analysis was conducted from data of two large Australian twin studies (n†=†1,835) having undertaken ophthalmic examination, namely, Twins Eye Study in Tasmania (TEST) and the Brisbane Adolescent Twins Study (BATS). Ordinal logistic regression was used to compute odds ratios and predicted probabilities for each category of eye colour by state.

Results: Tasmanian residence was associated with lower odds of darker iris colour (odds ratio 0.77, 95% CI [0.63-0.95]) signifying that participants living in Tasmania (TAS) are less likely to have darker-coloured irides than those residing in Queensland (QLD). For individuals living in Tasmania the predicted probability (TAS versus QLD) of having light blue eyes was greater (16.7 versus 13.3 per cent), approximately the same for green eyes and less for brown/dark brown-coloured eyes (6.2 versus 7.9 per cent).

Conclusions: We found a general trend of individuals living in the southern states (TAS/VIC) of Australia having lighter-coloured irides compared to those living in the north (QLD). This finding has potential implications for all epidemiological research conducted to explore differences in UV-associated disease frequency in Australia, as population heterogeneity may confound the estimates obtained.

Item Details

Item Type:Refereed Article
Keywords:epidemiology, eye colour, iris, twins
Research Division:Biomedical and Clinical Sciences
Research Group:Ophthalmology and optometry
Research Field:Ophthalmology
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Hewitt, AW (Professor Alex Hewitt)
UTAS Author:Mackey, DA (Professor David Mackey)
ID Code:106654
Year Published:2015
Web of Science® Times Cited:2
Deposited By:Menzies Institute for Medical Research
Deposited On:2016-02-17
Last Modified:2017-11-07

Repository Staff Only: item control page