After you fire up the barbecue grill, the charcoal briquettes you use as fuel are eventually reduced to a pile of charred remains and ashes. This residue contains recycled plant material and naturally occurring minerals, but it may also contain harmful chemicals.
Burst blood vessel in the eye. Straining, coughing or injuring your eye can sometimes cause a blood vessel to burst on the eye surface, causing a bright red blotch. This is called a subconjunctival haemorrhage.
Bleeding of the eye is usually caused by suffering an injury to the eye. 1  Less common but serious causes of eye bleeds include cancer, malformations of blood vessels in the eye, and irritation and inflammation of the iris (the colored part of the eye.) Small subconjunctival hemorrhages can result from forcefully sneezing or coughing.