How does Milton make his description of Paradise Lost dramatic?

John Milton's dramatic descriptions in Paradise Lost are effective because they appeal to all of the senses. For instance, Heaven is associated with light and brightness. He describes God's throne as shrouded in a cloudy type of mist because the light that emanates from him is so strong. The contrast to this, of course, is his depiction of Hell as dark. He writes,

As one great furnace flamed, yet from those flames
No light, but rather, darkness visible (I. 62-63).

It is paradoxical that the flames in Hell somehow give off darkness instead of light. Adding to his lurid depiction of Hell is the mention of the sulfuric fumes that attack Lucifer's sense of smell as the flames burn his body.
In book 1, Lucifer rallies his other fallen angels by saying,

Seest thou yon dreary Plain, forlorn and wilde,
The seat of desolation, voyd of light,
Save what the glimmering of these livid flames
Casts pale and dreadful? (I. 180-183).

This description is particularly powerful because Lucifer is admitting their loss of the light of Heaven and he does not make any attempt to glorify their new, painful surroundings. This makes his subsequent statement, that they lift themselves from the "fiery waves" and consider their next move, particularly poignant.
It is Milton's appeal to the senses that makes the descriptions dramatic. He elevates the light and goodness of Heaven in order to contrast it with the darkness and pain of Hell.