Isplack eyesticks are resistant to sweat and smudges and are not harmful to health
 
The eye black is a product, commonly an oily substance, applied under the eyes to reduce glare; it is often used by players of  american football e baseball, where sunlight or stadium lights can block the correct view of a ball thrown into the air.
 
"Eye black" has been used for centuries to reduce glare from the sun.
 
The traditional fat is considered to be made from beeswax, paraffin, and charcoal.
 
Anti-glare facial strips (patches) that emulate fat are commonly used.
 
One of the first players to use "black eye" was baseball legend Babe Ruth, who around 1930, used grease in an attempt to reduce glare from the sun.
 
According to ESPN's Paul Lukas the first American football player to use "black eyeball" was Andy Farkas who allegedly used burnt cork ash.
 
A study carried out in 2003 by Brian DeBroff and Patricia Pahk led to the conclusion that indeed the fat under the eyes had anti-glare properties.
 
The study subjects were divided into three groups: those who had applied grease "eye black", those who wore anti-reflection stickers, and those who had applied some vaseline.
 
Experiments with sunlight found that eye black grease significantly reduced glare caused by sunlight, while anti-reflection stickers and petroleum jelly were ineffective.
(cited from Wikipedia)
 
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