Blog #36
Happy New Year!
I have never said that with more emphasis than when we ushered in 2021. Here we were 2020, the year of the optometrist; after all 20/20 vision is that highly sought gold standard. The past year has been anything but golden. Do not get me wrong, there were some wonderful bright points to the year, but overall, good riddance.
That brings me to this chart that I have included here. This is where the whole idea of 20/20 originated. Back in the 1850’s, a renowned ophthalmologist, Dr. Franciscus Donders, from Utrecht, Netherlands, wanted to measure people’s visual acuity. He gave that task to Herman Snellen, one of his assistants. There had been eye charts before this but they were not standardized.
Snellen first started with a series of circles, squares and arrows but found universal response to them unreliable. He settled on letters and numbers of “optotypes”, with standard thickness, spaces and sizes on a highly contrasting chart. (The chart shown here has eleven lines while Snellen’s original had seven). The person would stand 20 feet away and cover an eye and read down the chart until they could not see it anymore. If the person could see the smallest line that a healthy unaided eye could see clearly, then they had 20/20.
The Snellen Eye Chart, before the dawn of computer generated versions, sold more copies in the United States than any other poster. It has been standard of practice ever since Snellen, with optotypes developed for many languages and alphabets. More recently the University of Waterloo developed the first Arabic eye chart.
Still today, one of the first tests we do on our patients, is a visual acuity using a Snellen chart. There have been many advancements since the 1850’s but the work of Donders and Snellen was the starting point in the era of modern eye care.
TZVECL, that is 20/20 in Snellen optotype. I wonder what the optotype for 2021 would be? Could it possibly be LETSHOPE?
Til next week, and remember to Stay Positive and Keep Negative,
The Good Doctor, Dr. Mark Germain, Burlington Eyecare
