We are in the century of innovative inventions. It seems that every couple of months something new comes out on the marketplace to make our lives easier , better or a more accurate assessment of say a health problem or not. But then there are the inventions that are informative and timeless and a gauge for important things like our precious eyesight. It happened about 107 years ago that the Dutch Ophthalmologist Herman Snellen died at the age of 73. You probably do not recognize his name but I am sure you recognize his invention that is still widely used to determine how well we can see.
Yes I am talking about the eye chart. The piece of cardboard stuck to the wall at least 8 feet away from you or the image projected on the wall from some very expensive modern equipment. It is still the same chart of letters that you must recite back to him or her that to some extent still determines how well or not your vision is. The chart is called the Snellen chart bearing the inventor’s name. I don’t know why they never tell us to read the Snellen chart, they just say name the letters in the order you see them from left to right.
The Snellen Chart features 11 lines of progressively smaller letters. They are not just any letters. They have been the same letters for over 100 years. It uses just 9 letters. C,D,E,F,L,O,P, T and Z. The font and clunky appearance and order have been carefully designed by Herman to test visual accuracy. It is also Herman Snellen who decided to read our vision as a ratio. If the patient could read a line of type 20 feet away, he proclaimed them to have 20/20 vision. And it would be the specific line, line number 8 that read DEFPOTEC in that order. The line above that is number 7 and is larger size font and reads FELOPZD representing 20/25 vision. Line number 6 is much larger and reads EDFCZP representing 20/30. The larger the ratio the larger the font. Line numbers 9,10, and 11 represent the smallest and most accurate vision on the chart but yet are not represented by a ratio. Of course Ophthalmology has far advanced further than anything Mr. Snellen could have imagined but yet his chart still remains as our first indicator of vision capabilities.
This week is Holy Week and Passover. Let us all be thankful to our creator for giving us our precious eyesight and giving talented people we don’t even know their names the wisdom to create better ways to manage our lives. Pray for peace and prosperity and good health.