Vision tends to go down hill magically at 40 for most people. Try readers and see if that helps with reading. Might be time for bifocals. I don't mind bifocals, but even with them, reading is a struggle for me. I've gone to reading mostly on tablets where I can adjust the font size. Otherwise, I find most print is just too small anymore and I have to take off my glasses and get the print close to my face. Whether you need bifocals or not much depends on how severe your prescription is for both near and far distance, whether you have astigmatism issues or not, how much switching back and forth you have to do regularly. As a teacher, I have to be able to move back and forth constantly between distance and close vision, so switching glasses constantly just isn't practical.