This video as short as 7 seconds it shows you the difference between the lung of a smoker and that of a non-smoker. Surely if you stop smoking it will be one of the best decisions of your life.
However, being rigorous, the lungs in this video are from pigs. In fact, smoking does not turn your lungs black as night, although it is true that they suffer a discoloration. It is also curious that in autopsies performed on smokers, on many occasions, one of the lungs looks moderately well while the other lung is usually more affected.
For a more realistic picture of what tobacco does to your lungs, try searching "Anthracosis" in Google Images. You will see that there is a well-established relationship between smoking and the physical appearance of the lungs.
If you find it very difficult to quit smoking, I advise you to try the new electronic cigarettes that are coming to the market and how fashionable they are lately.
In any case, I leave you with this short video that will make you think about this harmful habit:
I think this works and this guy doesn't know what he's saying