Who should you expect to show stronger red-eye effect?
there is no difference
The iris plays no role in the effect, but the blue-eyed people have relatively low melanin in the fundus as well. Therefore, they show a much stronger red-eye effect, as the light passing fundus is not absorbed by melanin. The role of melanin in red-eye effect is nicely demonstrated in case of heterochromia (one eye blue, one brown): typically, only the blue eye displays the effect.
reach: rather globaleyeslightphotography
Illustration: Michael Miller