As such some of what we see is just the brains interpretation of sensations from the eye structure and the pressure applied to it. Try rubbing your closed eyes and you will see what I mean. Always remember that the number one job of the brain is pattern recognition.
Emphysema is a form of chronic (long-term) lung disease, usually caused by smoking. Because of lung damage, people with emphysema have difficulty blowing air out. The major symptom of emphysema is shortness of breath.
What causes a pulmonary embolism? Blood clots can form for a variety of reasons. Pulmonary embolisms are most often caused by deep vein thrombosis, a condition in which blood clots form in veins deep in the body. The blood clots that most often cause pulmonary embolisms begin in the legs or pelvis.