There are glass-like plastic bucket lens of what is the reas

There are glass-like plastic bucket lens of what is the reason

 

     Used plastic barrels filled with water for a year to put useless today to show equipment used was found there like ice bucket lens of some small, colorless and tasteless, in the sun will become a white opaque, Volume also become smaller plastic buckets filled with water to put a year is useless today to show equipment used was found there like ice bucket lens of some small, colorless and tasteless, in the sun become white opaque, size also becomes smaller.