Snellen Chart
The most popular poster in history has nothing to so with Taylor Swift. Nor does it involve Albert Einstein sticking out his tongue. It’s the one that that you see on the wall of your optometrist.
The Snellen chart is a widely used tool for measuring visual acuity, developed by the Dutch ophthalmologist Herman Snellen in 1862.
Before Snellen, there was no standardised way to measure vision. Early attempts involved reading texts or recognising objects at a distance, but these methods were inconsistent. Working with …
