Bowie's differential eye coloring came not from heterochromia, but from a "lusty scrap".

I'm not even sure what that is. :)

Heterochromia is genetically differential eye coloring, which is very rare.  A lusty scrap is a boyhood fight over a girl (in this case).

Thank you for that description.

The iflscience article talks about lusty scrap and attributes Bowie's eye color to it, too.

Complete heterochromia is a fairly rare condition (in humans) whereby each iris is a distinctly different color.

So Today I learned something new.

Here's the story of David Bowie's eyes:

Anecdotally, the cause of Bowie’s anisocoria was attributed to the fallout from a lusty scrap in the spring of 1962. Bowie had come to blows with a friend, George Underwood, over a girl they were both hoping to date.

Both were just 15 at the time and their friendship seemingly remained intact. The two performed together in various bands before Underwood turned from music to painting and graphics. But Bowie’s left eye remained seriously damaged.

An impulsive punch had accidentally scratched the eyeball, resulting in paralysis of the muscles that contract the iris. From that day, Bowie’s left pupil remained in a fixed open position.

Over time, Bowie apparently thanked his friend for his notorious eye injury, telling Underwood that it gave him “a kind of mystique”. This mystique helped fuel some of Bowie’s greatest creations and enhance iconic images, such as the album cover for Heroes (1977).