Anti - reflective strips

The black "marks" under Chanderpaul's eyes are stickers he uses to help reflect glare away from his eyes. It is the same as you see with players in american football, and was commonly used before sunglasses to help keep the sun out of players eyes. He does not get them from a sponsor, he simply buys them from a shop. I think he does not like sunglasses, and he also wears them at night to prevent any glare from the lights.

Chanderpaul wore beneath his eyes - assumed it was advertising-gone-mad - but they’re anti-reflective-strips!