Which type of lens is typically used in magnifying glasses?

Magnifying glasses are designed to enlarge the appearance of objects, and this effect is achieved through the use of a convex lens. A convex lens is thicker in the middle than at the edges and converges light rays that pass through it. When you look through a convex lens, the light rays are bent towards one another, which creates a larger, upright image of the object being viewed. This ability to magnify is why convex lenses are commonly found in magnifying glasses.

Concave lenses, in contrast, diverge light rays which makes them useful for correcting nearsightedness but not for magnification. Flat lenses do not possess the curvature necessary to properly focus light for magnification purposes. Therefore, the use of a convex lens is the reason why it is the typical choice for magnifying glasses, making the identification of the correct answer straightforward.