Ok... Here are my Oliver designs for before and after the satellite.
My headcanons are under the cut
When the satellite hit the research vessel, he technically died, so he got some scars. He's blind in his left eye and sometimes uses prosthetics. One detail I think about a lot is that he had to swim to the nearest island. Imagine swimming that distance.
Before, he had beautiful, long, fluffy locs that Graham took care of. But after his mental health went south, he stopped caring for his hair. He also had snake bite piercings, which he started wearing while working at the 'magic' shop.
So, he's also tanned.
His scars took time to heal, and because of the swim, they healed a bit messily. He partially lost mobility in his right leg, left arm, and both hands (his left side being the most affected).
From afar, his scars look like vitiligo.
Now, he doesn’t wear any piercings, but he does wear eyeshadow and eyeliner. His hair is short and box-braided, with two long side braids. I also like to think his eyes absorb light, making his pupils look shiny instead of black.