Like blue eyes, gray eyes have a dark epithelium at the back of the iris and a relatively clear stroma at the front.
Gray eyes are most common in Northern and Eastern Europe. Gray eyes can also be found among the Algerian Shawia people of the Aurès Mountains in North West Africa, in the Middle East, and Central and South Asia. Under magnification, gray eyes exhibit small amounts of yellow and brown color in the iris.
A gray iris may indicate the presence of a uveitis. However, other visual signs make a uveitis obvious. Gray and blue eyes are at increased risk of uveal melanoma.