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.
Broken capillaries in the eye also called subconjunctival hemorrhage, and causes the red eye until, in one day days, blood was completely absorbed. Usually, the problem tends to remit spontaneously, but if in doubt, it is best to always consult your doctor.