Almost everyone is born with limbal rings, but most people lose them as they age. Some people find limbal rings very attractive in a partner. Losing your limbal rings (or still having limbal rings into your 30s and beyond) doesn't indicate any health condition, and it's not a cause for concern.

At what age do limbal rings fade?

In general, limbal rings begin to decline in one's 20s, disappearing altogether in old age. Limbal rings are more prominent in people with lighter colored eyes, subtly enhance the eyes, and make the whites of the eyes appear whiter.

What is the rarest eye color?

The production of melanin in the iris is what influences eye color. More melanin produces a darker coloring, while less makes for lighter eyes. Green eyes are the rarest, but there exist anecdotal reports that gray eyes are even rarer. Eye color isn't just a superfluous part of your appearance.