Concave Lens: Definition, Formula, Uses & Image Formation

Concave lens is a diverging lens that spreads out light rays having been refracted through it. It diverges a straight light beam from the source to a diminished, upright, virtual image. A concave lens possesses at least one surface curved inside. It can form both real and virtual images. It is thinner at its center compared to its edges, and is used to correct short-sightedness. 

What are Concave Lenses?

A concave lens diverges a straight light beam from the source to a distorted, upright digital picture. It is capable of developing actual and digital snapshots. A concave lens has at least one internally curved floor. Because it’s miles are rounded at the center and bulge outward on the borders, inflicting the light to diverge, a concave lens is likewise known as a diverging lens. They are used to treat myopia because they make distant items appear nearer than they are.

Concave Lens Formula

The kind and location of the image created by the concave lens are determined using the lens formula. The lens formula is: 1/f = 1/v + 1/u


v = the distance of the image from the center

u = the distance of the object from the center

f = the focal length.

Like that, the equation below shows the image magnification: M = hi/ho = v/u


M = the magnification

hi = the height of the image 

ho = the object’s height.

Image Formation in a Concave Lens

A virtual picture of the item at infinity appears at the focus. The picture is substantially smaller than the thing in size.


A virtual picture of an item is created between the convex lens’s pole and focus when it is put at a specific distance from the lens. Because of this, the image’s size is less than the objects.


Uses of Concave Lenses

About the surface plane, a concave lens has at least one surface that is bent inward. A concave lens’ center is significantly narrower than its corners. Light beams bend outward and diverge away from one another as they strike a concave lens. The picture, which was smaller than the actual thing, was generated upright. The uses of concave lenses that are intriguing and widespread are listed below.

List of uses:

  • Applied to Telescopes
  • Utilized in eyewear
  • Used in Peepholes
  • Laser applications for concave lenses
  • Cameras with concave lenses

Applied to Telescopes

In telescopes and binoculars, bursiform lenses are accustomed to enlarge things. Bursiform lenses are units inserted before or inside the lens of telescopes and binoculars as a result of lentiform lenses blur and deform pictures, creating them more durable for users to concentrate.

Utilized in eyewear

Nearsightedness, or myopia, is most often treated through victimization by bursiform lenses. ametropia causes the eyeball to be fault extended, which causes footage of distant objects to miss the membrane. Bursiform lenses are a unit so utilized in spectacles to form up for the disadvantage by spreading out the sunshine rays before they reach the attention. The person will clearly understand distant objects as a result.

Used in Peepholes

Peepholes or door viewers square measure security devices that provide a perspective of objects outside walls or doors. A diverging lens is employed to attenuate the proportions of the items and provides a wider read of the object or space.

Laser applications for concave lenses

Laser beams are used in a variety of scanners, medical devices, and CD and DVD players. The apparatus functions correctly because the laser beams, although extremely concentrated, are distributed. The laser beam is widened by small concave lenses, allowing it to more clearly access a particular location.

Cameras with concave lenses

Combinations of convex and concave lenses are frequently employed by camera makers to enhance the quality of images. Chromatic aberrations are distortions that appear in photographs when a camera’s primary lens is merely a convex one. Concave and convex lenses combined removed the negative effects.