I hope you enjoy my theories! I wrote this during school so please bear with me.

As we all know, the reapers in Black Butler have green-chartreuse phosphorescent eyes and glasses. But why? We are told that the reapers are terribly nearsighted, but that doesn’t explain what the nearsightedness or green eyes represent. I have my own theories on these and would like to share them!

Glasses - As we know, in chapter 105, it was confirmed that reapers were once humans that committed suicide, and reaping souls is their “punishment”. With being a reaper comes nearsightedness, which is why they wear glasses. I believe that the glasses represent how, as humans, they did not “see” the future or the consequences of their deaths when they killed themselves.

Eyes - The green eyes of the reapers are usually what gives them away, as they are an unusual shade of green-chartreuse. These two colors represent many things, but the most notable is envy. It is possible that the green eyes represent the envy they felt towards those who led happy lives while they were suffering and jealousy of the humans who don’t have to work tirelessly for one sin. Green can also represent depression, which has links to suicide.