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.
A broken blood vessel in the eye is known as a sub-conjunctival haemorrhage. It can look pretty horrific (as in the above image), but it will not cause any damage to your eyesight. It is, however, cosmetically unpleasant. Normally, the first thing you will notice is an unsightly red patch over part, or all, of the white of your eye.