Eye Strain.
(Post written last night; I needed to sleep on the grammar.)
Like hangovers and awkward conversations about birth control with your in-laws, eye strain would only exist in myth were it not for humanity's perpetual lack of forethought and patience. Case in point: I just spent eight hours at work engaging with a computer's screen via its keyboard, one hour reading a 12 font book on the train ride home, and am now--immediately following this workday and commute--typing this onto a much smaller keyboard with a much smaller screen. I thought the drop of blood that fell from my face to my pants was from my eyes. Turns out it was my nose. I wouldn't have been surprised if it had come from my eyes.