Ever wondered who invented the chart of letters your ophthalmologist uses to check your eyesight every time you visit!? Want to know some exciting facts which you never knew about the pair of eyes you possess?? Go on, read along!!!
Well, it all started with this humble man named Ferdinand Monoyer. Ferdinand was born in Lyon, France in 1836. His father was a Military doctor by profession. He was a pioneer in ophthalmology. He is credited for the invention of the Dioptre in 1872. He was the Associate Professor of Medical Physics at the Faculty of Medicine, the University of Strasbourg in 1871.
Ferdinand introduced the now-widely used Monoyer chart for testing visual acuity. In order that no one could steal his creation, he placed his name in the letters of the chart. To uncover his name, you have to read vertically from bottom to top on each side of the chart. And ophthalmologists all across the globe employ this tried and tested method for finding out any person’s eye power effectively and accurately.
Google Doodle
This method has not changed since. The process for measuring the sharpness of the eye is quite simple. The examiner is asked to read aloud the letters starting from big to small from the chart which is hung at eye level at some distance.
And now its time for some fascinating facts about the eyes with which you see the world:
A human eye weighs approximately 28g, is 2.5cm wide and has six muscles
They hardly grow from the time when you’re born
Eyes can only see the colours red, blue and green. They make all others from these three
They can spot around 50,000 shades of grey
The average blink takes one-tenth of a second
People blink around 12 to 17 times per minute
It takes an eye 48 hours to heal a scratch
There are around 137 million rod and cone cells in your eyes
The muscle that controls the eye is the most active in the body
Images arrive at the eye upside down, split in half and distorted
Peripheral vision is of low quality and almost black-and-white.