A lens enables us to see things around us, to see different colors, and to make differences between various objects. Our eyes, through which we see the world, have a crystalline lens. This lens is transparent in nature. This lens has a biconvex structure, and along with the cornea, it refracts light rays to be focused on the retina. Lens do both refract as well as a focus light.
The curve of a lens makes the whole difference as its shape determines in which direction and to what extent the light is going to bend. Based on its shape, a lens can be defined as a concave and convex lens. The convex lens also is known as a converging lens as it converges the light to form an image on the other side.
Concave vs Convex Lens
The main difference between Concave and Convex Lens is that the concave lens refers to the lens which disperses the light rays when contacted with the lens. A concave lens is used for myopia to correct shortsightedness, but a convex lens is used to correct hyperopia to correct farsightedness.
A convex lens refers to the lens through which light rays pass when contacted. In a concave lens, objects appear smaller and far whereas in convex lens objects appear bigger and large.
Comparison Table Between Concave and Convex Lens
| Parameter of Comparison | Concave Lens | Convex Lens |
|---|---|---|
| Definition | It is a diverging lens that spreads out the light. | It is a converging lens which converges the refracted rays. |
| Curve | The curve is outward in it. | The curve is inward in it. |
| Image and Objects | The image formed is real, and the object appears closer and larger. | The image formed is virtual, and the object appears smaller and at a great distance |
| Focal Length | The focal length is positive. | The focal length is negative. |
| Usage | Used to correct the problem of short-sightedness or myopia. | Used to correct the problem of farsightedness or hypermetropia. |
What is Concave Lens?
Curiosity is the mother of invention. Every
scientific experiment starts with a zeal to discover something new, and we can
assume that the same interest brings the idea of the lens, their types, and,
most importantly, their uses.
Objects could be perceived with different images and can be applied in many cases also. A concave lens has a thinner center and thicker edges. Its surface is inwardly curved. It spreads the light rays falling on its surface, and that is why it is also called a diverging lens.
There is a specific point where the light rays converge
after getting reflected. This point is known as the principal focus of the
concave lens. At this point, the parallel light moving to the axis of the lens
is focused.
The images formed by the concave lens are always virtual, upright, and smaller than the object. The size of the virtual images increases because the distance between the lens and object decreases.
Concave lenses are used in eyeglasses, telescopes, flashlights, side mirrors of cars and motorbikes, movie projectors, etc.