How do convex lenses differ from concave lenses?

Convex and concave lenses differ primarily in their physical shape and how they manipulate light:

• Physical Shape: A convex lens is thicker at its center than at its edges, whereas a concave lens is thicker at its edges than at its center.12
• Light Manipulation: Convex lenses are converging lenses, meaning they cause light rays passing through them to converge at a focal point. Concave lenses are diverging lenses, causing light rays to appear to diverge from a focal point.32
• Focal Length and Imaging: For a convex lens, the focal length is positive. Depending on the object's distance, it can form either a real or a virtual image. For a concave lens, the focal length is negative, and it exclusively forms virtual images.1

These distinct optical properties make them suitable for different applications, such as correcting vision or focusing light in instruments like cameras, microscopes, and telescopes.24