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.
Subcutaneous emphysema can be caused by medical procedures and medical conditions that cause the pressure in the alveoli of the lung to be higher than that in the tissues outside of them. Its most common causes are pneumothorax and a chest tube that has become occluded by a blood clot or fibrinous material.