A convex or convex lens focuses the light ray on a specific point, while a convex or divergent lens deflects the light rays. A lens is a transparent object (curved or flat) based on the principle of refraction.
Convex lenses and convex lenses are often used together in what is known as concave – convex lenses. Together, these lenses produce sharp images.
Most contact lenses use a combination of convex and curved lenses. Cameras, telescopes and binoculars use a variety of lenses to help us see the world clearly.
What is Convex Lens?
Concave lenses (sometimes called positive lenses) have glass (or plastic) surfaces that float from the center. A convex lens is also called a converging lens because the various passing light rays bend inward and focus (converge) at a point just beyond the lens known as the focus.
What is Concave Lens?
A concave lens where the outer parts curve inward is the opposite, causing different light rays to curve outward or diverge. This is why contact lenses are sometimes referred to as discrete lenses. By thinking internally about convex lenses, the disparity between concave and concave lenses will become clearer.
Types of Concave Lenses
There Are Three Types of Concave Lens
- A long lens with one concave region and one flat surface with poor central thickness.
- Concave-convex lenses The curvature of the concave face is less than that of the concave face, so that the former extends further than the latter.
- Double concave lenses are also referred to as double opposite lenses which have the same radius of curvature on both sides of the lens and operate similarly to narrow concave lenses resulting in a flat lens.
Types of Convex Lenses
- A biconvex lens is a simple lens consisting of two convex spherical segments, generally with the same radius of curvature.
- These lenses are positive center length elements with one spherical and one flat region. They are designed for use in an infinite circuit (coherent light) or simple imaging in low intensity applications.
- By focusing a beam of light from distant objects from its focus through a biconvex lens, the gray lens is convex when viewed from one side and convex from the other as shown in the figure below:
Difference between Concave and Convex Lens
| Concave Lens | Convex Lens |
| The light is spread out by a diverging lens. | The refracted rays are converged by a converging lens. |
| Thinner in the centre than at the edges. | Thicker in the centre than at the edges. |
| The image is on one side of the lens, while the object is on the other. | The object and the image are both on the same side of the lens. |
| The focal length is positive. | The focal length is negative. |
| The image will be erect, virtual, and diminished. | The resultant image will be both real and inverted. |
| Eyeglasses for myopia (nearsightedness) | Eyeglasses for hyperopia (farsightedness), magnifying glasses |
| Applications include correcting nearsightedness, creating virtual images | Applications include correcting farsightedness, magnification, projectors |
