We may come across major things in our day to day life. Most of the times we fail to notice the strange thing in it. For example, let us consider an elevator. An elevator is very familiar for us. We use them daily in the apartments, office buildings, shopping malls, multiplexes etc. You may have noticed the elevator button many times. But here is one thing which is strange to you. Have you ever noticed little dots under the elevator buttons? Though you press those buttons more frequently, you may not know the hidden meaning behind them.
Once notice the buttons clearly which were in the below picture

Have got any clue by seeing this? Just see the pic for one more time
Here is a clue for you. Just think about how a blind person uses the elevator
The answer is Braille Writing System:
Braille Writing System is for the blind people or visually impaired people. The dots helps the blind people to read the function of the button. They sense it by touching with the fingers.
About Braille Writing System:
Braille is named after its creator, Frenchman Louis Braille, who lost his eyesight due to a childhood accident. In 1824, at the age of 15, Braille developed his code for the French alphabet as an improvement on night writing. Braille characters are small rectangular blocks called cells that contain tiny palpable bumps called raised dots. The number and arrangement of these dots distinguish one character from another.
Isn’t it fascinating? So don’t fail to notice this dots on the elevator buttons whenever you are going to use them.
Also Read: Do you Know What Does This Symbol On Every Power Button Mean?