The eye of David Bowie isn't even technically a different color. If it wasn't permanently dilated, it'd actually be the same color as his normal eye. It's an optical illusion that it's a different color (something to do with the squashed down iris&.due to the dilation).
Plus, it wasn't an accident. He was punched in the face when he was young for trying to steal another guy's girlfriend. It got all swollen and stuff, they thought it might not work after that, but it healed up. So, it's his rea.l eye, it's just dilated all the time.
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