I have prescription glasses for reading, but I wear them all the time because they are comfortable and keep me from getting headaches every day. I was prescribed them even though I passed the vision test that was given to me.

When I was going through Boot Camp, I passed the mandatory vision test and was told that my eyes were fine and I would not need glasses. Then I took another vision test shortly after getting to my first tour station and the lady said "Whoever said you didn't need glasses is an idiot."