The worst was the time I got hit in the face by a volleyball in gym class and had to go the rest of the day with no glasses. If I wanted to have a prayer at reading the board, I had to move my desk practically on top of the teacher.
Spare glasses are a necessity to me. I have two pair. I own a glasses-repair kit.
Were I in a similar situation, no teacher would even ask me, my vision was so famously bad in high school.
Legally blind starts at 20/400 vision. Without correction, mine's in the 20/1600 range, meaning I have to be 20 feet to see something normally-sighted folk can see from about a third a mile away.
In third grade, I went on a field trip to an orchestra without my glasses, and the teacher asked us to write about what our favorite instrument was. Everyone else said stuff like, 'the trumpet looked cool!' Mine boiled down to 'I liked the fuzzy one. The one with the funny name. It looked fuzzy.'
My basketball coach called me Velma, despite my being a male, after I stopped basketball practice because my glasses fell off. My reaction was loud, to say the least; it stopped not only the boys' practice, but the girls' as well, on the other end of the court.
Like I said, if we presume Clinton to be accident-prone and poorly-sighted, I understand why he would keep multiple pairs.