Cold sore: Viruses or localised infections can cause the eye to redden â the problem usually starts in one eye, but can spread to both. The cold sore virus, which 90 per cent of us carry, can sometimes also infect the eye, causing inflammation.
Endorphins are chemicals, called peptides, that are made in the body. They have much of the same effect on a person as opium or morphine. As a result, they actually lower the feeling of pain in the body and can create a feeling of bliss or euphoria.
More About Endorphins: Because they are naturally produced by the body, endorphins are possibly the best (and most legal way) to achieve a natural high. Chemically speaking, endorphins are polypeptides, which are able to bind to the neuro-receptors in the brain to give relief from pain.