21 July 2020

Difference Between Concave and Convex Lens

Concave and convex are two types of lenses that posses variation in physical shape as well as their properties. Here this article gives the basic difference between concave and convex lens to better understand this topic.

Definition of convex lens:

A convex lens is the lenses that feel massive at the centre than at the edges. The curve of the lens is outward, and as the light beams pass through the lens, it refracts them and brings them together, resulting in the convergence of light, due to which it is also named as a converging lens.

Definition of concave lens:

Concave lenses represent the type of lenses which are slender at the centre than at the border. The shape of the concave lens is round inward that bends the beams outward, causing divergence of the rays of light falling on it, so it is knowns as a diverging lens.

Difference between concave and convex lens:

  • Concave is thin at edges and thick at the center while a concave lens is this at the center but thick at its edges.
  • The focal length of a convex lens is positive, while the concave lens has a negative focal length.
  • The curvature of a convex lens is outward-facing, whereas the curvature in a concave lens if inward-facing.
  • A convex lens is used to correct hypermetropia, long-sightedness while in a concave lens corrects myopia.
  • A convex lens can form virtual as well as the real image of the object according to its distance from the lens, whereas the concave lens forms an only virtual image of the object.
  • The concave lenses are used to cure myopia while the convex lens corrects hypermetropia.
  • Convex lenses hold magnifying abilities thus are generally used in the lens of microscope and telescope but in the 
  • the convex lens is used in laser, flashlights of vehicles as well as peephole of doors.
  • A convex lens has to convert nature as it merges the light passing through it and focuses them at a particular point. While in a concave lens has diverging nature as it diverges the light rays passing through it. 
  • Due to the nature of the lens, the incident light rays either converges or diverges after passing through it. Thus, the concave lens is also known as a diverging lens while the convex lens is known as a converging lens.
  • Convex lenses hold magnifying abilities thus ar generally used in the lens of microscope and telescope, Also the human eye lens is concave in nature. But a convex lens is used in lasers, flashlights of vehicles as well as peepholes of doors.  
  • These two lenses are a cave-like structure from outside as it has a thinner middle portion and thick edges. However, in the convex lens, the edges are comparatively thinner than the centre of the lens.
  • In case of a concave lens, the body or object near it appears to be present at distant and is smaller than the actual one. However, when a body is present in front of a convex lens than it appears in a way that it is present nearer and is of larger dimensions than the original body.