These are glasses that are focused for viewing near objects … such as when reading a book. Inexpensive, over-the-counter reading glasses work well for many people and range in diopter power from weak +1.00 glass, all the way up to +3.50 readers. The power of your “cheaters” depends upon your age and how close you like to hold books to your face. If you have significant refractive error (nearsightedness, farsightedness, or astigmatism) you may require prescription reading glasses (or a bifocal) for best vision. Also, keep in mind that cheap OTC reading glasses are designed to fit the average person … if your eyes are narrow or wide-set, they may not be as comfortable or clear as a custom glass. Your need for reading glasses occurs because of presbyopia (aging changes inside the eye), and is normal after the age of forty.