Odd sight
I don't have anywhere near perfect eyesight. My other eye sees relatively well to a distance and the other is good at close up. So in most situations I do just fine without glasses. Unfortunately the area of vision of my eyes doesn't overlap. At around one meter away neither of my eyes can focus enough to make up What's there.
Due to this "blind" area I have to use glasses mostly when working on a computer. The viewing distance for an ergonomically comfortable posture falls right into my area of poor vision.