Iris (Definition) The iris is a structure within the eye that helps reduce the amount of light that reaches the retina. The iris is known as the colored part of the eye, and can be blue, brown, or any color or combination of colors in between. The iris is the portion of the eye that responds to light stimulation. ...Read more.
Scientists also speculate that caffeine may provide a mood-boosting effect that helps ease pain. Regardless of the mechanism by which it works, the data does indicate that caffeine does indeed make pain medications more effective and help ease pain.
Abdominal Pain. Many people attest to the fact that caffeine is a stomach irritant. Even avid coffee drinkers will admit that their beloved beverage causes varying degrees of abdominal pain. Along with coffee, other caffeine sources cause abdominal pain and cramping, even diarrhea.he Mayo Clinic defines moderate caffeine use as consuming 200 to 300 mg per day, or two to four cups of coffee, and heavy caffeine use as consuming 500 mg or more of caffeine per day.