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.
Emphysema destroys alveoli, which are air sacs in the lungs. The air sacs weaken and eventually break, which reduces the surface area of the lungs and the amount of oxygen that can reach the bloodstream. This makes it harder to breathe, especially when exercising. Emphysema also causes lungs to lose their elasticity. Emphysema is one of the two most common conditions that fall under the umbrella term chronic obstructive pulmonary disease (COPD). The other major COPD condition is chronic bronchitis. Emphysema is an irreversible condition, so treatment aims to slow its progression and minimize symptoms.