The dark substance applied under the eyes, commonly used by athletes in outdoor sports, is designed to reduce glare from sunlight or stadium lights. This substance often comes in stick or grease form and is applied in stripes or smears beneath the eyes. A common example includes the application of black stripes under a football player’s eyes before a game.
Its primary function is to improve visual acuity in bright conditions, potentially enhancing performance. Historically, similar substances were used by warriors for camouflage or intimidation, suggesting a psychological dimension beyond pure functionality. The reduction of glare can lead to improved contrast sensitivity, enabling athletes to track objects more easily and react faster.
