Lateral Inversion Of Image

All of us must have seen an ambulance at least once.

We must also have observed that the word AMBULANCE is not written properly on the ambulance.

The reason behind it simple. The people in front will see the vehicle behind in their rearview mirror.

When we look at the image of it in our mirror we can observe that it is spelt correctly. Now they know that an ambulance is behind them and they will make way for it.

This phenomenon is called lateral inversion of images.

Let us try to understand this phenomenon.

Let's stand in front of a mirror and do this small activity.

When we wave our right hand, it seems that in the mirror the image is waving its left hand.

When we move towards the mirror the image also move towards the mirror. When we move away from the mirror the image also moves away from the mirror.

But if we move to our left the image moves to its right which is to our left. If we move to our right the image moves to its left.

"Lateral" means "sideways". In a plane mirror, each point on the image is as far behind the mirror plane as the corresponding point on the object is in front.

Now let's see the lateral inversion in alphabets.

The alphabet P appears in the mirror like this.

Similarly in the mirror images of alphabets look like this.

Some letters in the alphabet like A, M, T, O, U, W, X, Y remain unaffected after lateral inversion

Each letter will appear as its mirror image and the whole word will appear from right to left in the mirror.

Lateral inversion in a periscope.

A periscope is a device with two mirrors arranged parallelly at as shown above.

Here, we use two mirrors and the reflection of the tree takes place twice before the light reaches the eye.

So inversion takes place twice and the image is as it is. So lateral inversion does not take place in a periscope.


Lateral inversion is the apparent reversal of the mirror image's left and right when compared with the object.

It is used in Ambulances so that drivers of vehicles in the front can get an indication that an ambulance is passing by.

Some symmetric shapes like A, T, O, U, W, X, Y remain unaffected by lateral inversion.

There is no lateral inversion in case of periscope because there are 2 mirrors and the inversion takes place twice.

The End