Readers can be both prescription eyeglasses and non-prescription eyeglasses. When it comes to prescription readers, the prescription script written by an eye doctor is required. Prescription readers are always of high quality and more expensive than non-prescription readers. They are customizable to special vision needs and for different powers in each eyes. Non-prescription readers are over-the counter readers. They require no verified prescription from an eye doctor. Because of this, they are termed non-prescription glasses. however, they still have a specific magnification - usually ranging from +0.25 to +6.00 - in each lens, which is called a "power"or "strength". Where it gets confusing is that this means they still technically hold a prescription, but the prescription is set and is the same magnification level for each eye.Simply put, non-prescription reading glasses are glasses that you do not order from an optometrist or ophthalmologist. They can usually be found in retail stores, at the pharmacy, or online.