If you wear prescription lenses, rely on your vision, not just the calendar, to dictate when you might need a new prescription. Eyeglass prescriptions for refractive errors such as nearsightedness, farsightedness, and astigmatism may require revisions in less than a year’s time. If you wear reading glasses, your ability to read print may also decline quickly at certain stages. During teen years, nearsightedness may increase more than at other times in a nearsighted person’s life. Similarly, people with cataracts, as well as those who have vision problems after surgery, may find that they require updated prescriptions. In all cases such as these, there is no specific timetable for visits to the eye professional. Your eyes will tell you. Routine eye exams can detect vision problems, eye disease, and general health problems before you are aware a problem exists. If you need a new eyeglass prescription, ask about high-index lenses that are lighter and thinner than regular prescription lenses.