Ever wondered how we can perceive and see different things? Reflection and refraction are both phenomena that depend on the properties of light, the reason we can see different things.
Reflection vs Refraction
The main difference between reflection and refraction is that reflection gives out the perfect image or representation of the image whereas refraction provides a distorted image.
Reflection is the phenomenon when the light that strikes on a surface or a medium bounces back into the same medium, instead of going through the medium. This is what forms images and these images are commonly known as reflection.
Refraction is when the propagation speed of the light rays changes on striking a medium and they change their direction along with it. But they do not form a perfect image of the object, instead form a distorted one.
Comparison Table Between Reflection and Refraction
|Parameters of Comparison||Reflection||Refraction|
|Meaning||The light ray, on striking a surface bounces back into the same medium||The light ray, on striking, changes its propagation speed and direction|
|Surface||Mostly happens on a shiny surface like a mirror||Mostly happens on transparent surfaces like a lens|
|Angle of incidence||It is equal to the angle of reflection||It is not equal to the angle of refraction|
|Image formation||A perfect or almost perfect representation of the actual object||The image formed is distorted and it depends on the angle of incidence|
|Propagation speed||No change is recorded||The propagation speed changes.|
What is Reflection?
Reflection is the phenomenon of light when the light rays strike on a medium but it is bounced back into the same medium instead of entering the second medium.
This phenomenon is commonly observed in shining and smooth surfaces. These surfaces usually reflect most of the incident light rays forming a perfect or an almost perfect replica or image of the object. The number of reflected rays does not only depend on the smoothness of the surface but also the physical properties of the object that is to be reflected.
Reflection works on the laws of reflection. This law states that the angle of incidence is always equal to the angle of reflection. This law also states the incident ray, the reflected ray and the normal should always lie in the same plane.
The human eyes can perceive the colour of various objects due to reflection and the reflective properties of each object. The objects absorb some and reflect some of the light rays of a specific wavelength. The reflected rays are what determines the colour of an object.
What is Refraction?
Refraction is when the light rays incident on a surface or medium, instead of bouncing back, enters the medium but also experiences a change in their propagation speed and direction of propagation.
This phenomenon is commonly observed in transparent surfaces like glass or lens. The surfaces instead of reflecting the light waves enter the medium to form a distorted image of the object. The distortion of the image depends on the angle of incidence and the angle of refraction.
Similar to reflection, refraction also works based on laws known as laws of refraction. This law states that the common ratio between the angle of incidence and angle of refraction is known as the refractive index. This measures the characteristic of refraction for the medium and surface. Also, the angle of incidence, the angle of refraction and the normal should lie on the same plane.
This phenomenon is what helps the human eyes to perceive different objects around us. The light rays reflected from different objects are refracted by the lens of our eyes, which then converges at the retina to form the image. For corrected lens, the light rays undergo two refractions before it converges at the retina.
Main Differences Between Reflection and Refraction
- Reflection and refraction treat the light rays differently on striking the surface. During reflection, the light bounces back into the same medium. But during refraction, the light enters into the medium but it experiences a change in the propagation speed and direction.
- Although they are both properties of light rays, they are seen on different surfaces. For reflection to happen a shining surface such as a mirror is used. But for refraction, a transparent surface such as a lens is used.
- Since the two depends on two different laws, the properties of the angle of reflection and refraction are also different. The angle of reflection is always equal to the angle of incidence of the light ray on striking the surface but the angle of refraction is not equal to the angle of incidence during the phenomenon of refraction because it is seen that the light ray changes direction.
- The propagation speed during reflection does not change as there is no change in medium. But for refraction, since the direction and the medium changes, this changes the refractive index and therefore changing the propagation speed of the light rays as well.
- The medium of propagation of light ray does not change during reflection, because the light rays only to bounce back to form a replica of the image in the medium. But during refraction, there is a change in the medium because the light rays enter the second medium on incidence.
Reflection and refraction are phenomena related to the properties of light rays.
Reflection is when the light ray bounces back on striking a surface. Depending on the surface and the characteristics of the object, all of it or part of it is reflected. The reflected rays are what determines the colour of an object.
Refraction is when the light ray changes its speed and direction on striking a surface. The refracted rays, unlike reflected rays, forms distorted images of the object instead of a perfect replica of it. This is the phenomenon that helps the eyes to perceive the object’s image.
Together, reflection and refraction give vision and colours to the dull world around us.