Who developed the letter chart that is in all opticians' offices?

Snellen eye chart. A snellen chart is an eye chart used by eye care professionals and others to measure visual acuity. Snellen charts are named after the dutch ophthalmologist herman snellen who developed the chart in 1862. Vision scientists now use a variation of this chart, designed by ian bailey and jan lovie.
Snellen chart. Now that there are so many electronic versions, the classic rows of letters are less common.