I also did some training with an air pack; the heavy tank went on my back and my mask and air supply were connected by a thick rubber tube.
There was one air pack drill that I heard about but was glad I never experienced. It involved completely taping over a mask to keep it absolutely dark. Then, the firefighter would follow along an obstacle course of sorts by staying with his hose line. This would simulate a fire where the smoke would be so bad that a firefighter, crawling on the ground, couldn't rely on his vision to help find the exit.
I'm glad I never had to do it. The thought of the tight confines of the pack's mask and the complete loss of sight gave me a sense of claustrophobia. I like sight; darkness can scare me.
Today we read John Fletcher's view on the spiritual sight available to believers but not unbelievers. We continue with Christ Manifested:
"Let us begin with SIGHT : St. Paul prayed that the eyes of his converts might be enlightened; 'that you might know what is the hope of His calling.' He reminded them that Christ had been 'evidently set forth crucified' before their eyes. He assured them, that 'the god of this world hath blinded the minds of them which believe not' the gospel, and declared that his commission was to open the eyes of the Gentiles, 'and to turn them from darkness to light.' Abraham saw Christ's day, and was glad. Moses persevered, as seeing Him who is invisible. David prayed 'Open thou mine eyes, that I may behold wondrous things out of thy law.' Our Lord remarked that the heart of unbelievers 'is waxed gross, and their ears are dull of hearing, and their eyes they have closed, lest at any time they should see with their eyes, and hear with their ears, and should understand with their heart, and should be converted.' He counselled the Laodiceans to 'anoint thine eyes with eye-salve, that thou mayest see'; He declared that 'the world cannot receive' the Spirit of truth 'because it seeth Him not'; that the things which belong to peace are hidden from the eyes of an unbeliever; and that the pure in heart 'shall see God'. John testified that the man who does evil 'hath not seen God', and that 'darkness hath blinded the eyes' of the man who does not love his brother."Is the pastor of Madeley speaking of physical eyesight? No, he is referring to spiritual eyesight, something hard (if not impossible) to explain but real, nevertheless. Fletcher continues:
"The eyes referred to are those with which believers see the salvation of God; they are so distinct from those of the body, that when our Lord opened them in Paul's soul, He caused scales to grow over his bodily eyes. Also, no doubt, when Christ gave outward sight to the blind, it was chiefly to convince the world that He is the One who can say to blind sinners 'Receive your sight; see the goodness of the Lord in the land of the living; look unto Me, and be ye saved.'"The thought of losing our spiritual sight should terrify us. Let us continue to see God within our souls.