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.
Spontaneous subcutaneous emphysema is thought to result from increased pressures in the lung that cause alveoli to rupture. In spontaneous subcutaneous emphysema, air travels from the ruptured alveoli into the interstitium and along the blood vessels of the lung, into the mediastinum and from there into the tissues of the neck or head.