Who Invented The Standardised Eye Test?

Whenever someone goes to the opticians to look for help with their eyesight, the first step in almost every single case is to have that person read from an eye chart.

This standardised eye test is such a universal experience that almost every single child in the country has read from the chart, and people eligible for free eye tests can claim them every two years.

The standardised eye test is used not only for prescribing glasses but also for checking minimum standards for vision, such as whilst driving.

Whilst glasses have existed in some form since the 13th century, the first person to set up a standardised vision chart was Heinrich Kuchler in 1835.

 An ophthalmologist based in Darmstadt, Germany, he first developed an eye chart consisting of objects that patients needed to identify that decreased in size as a patient progressed through the order.

Relying on objects is not an ideal approach, as there is an inherent assumption that everyone knows an object and uses the same word for it. It was functional but not optimal, relying on drawings cut out of almanacks and calendars glued to a sheet of paper.

However, before he could make adjustments, he was shockingly arrested and imprisoned for three years for his involvement with a Burschenschaft, a student association at the time considered to be an anti-authoritarian political movement.

After getting his freedom in 1839, he continued his practice and by 1843, he had developed the first example of the standard optical vision test chart we know today, featuring twelve lines of letters of decreasing size.

He developed three charts so people could not simply memorise the test, but it took decades for his idea to get off the ground, thanks to the later work of Eduard Jaeger von Jaxtthal, Herman Snellen and Edmund Landolt throughout the remainder of the 19th century.