system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: What happens in sleep that 'cures' puffy eyes and eyebags, and are we able to replicate this while avoiding sleeping?
gpt
Skin under our eyes are particularly very thin and become lax very easily.. this makes them more transparent to whatever happens under the skin, for example if the blood supply increase it soon starts to look darker than the skin around, also minimal changes in fluid retention under the skin makes the undereyes look saggy. The exact connection between saggy eyes and lack of sleep has not been identified... However, it can be explained that when the eyes overwork and not get the rest that it needs, just as the eyes look reddened because of the increasing blood supply, the skin under the eyes also darken and creates an illusion of making it look kinda saggy... However oversleep can cause saggy eyes because the horizontal position of the body makes the extracellular fluid to accumulate around the face, making the face puffy and under-eyes particularly saggy.