Mind Your P's and Q's – A Look At The Eye Chart

A brief history of the eye chart: the typical "Snellen Chart" is named after a Dutch Ophthalmologist who designed the chart in 1862 and is comprised of block letters. These letters have a standard and specific geometry, with each black line being the same thickness as each space within the letter, and the height being five times the size of each block. Originally, only the letters C, D, E, F, L, N, O, P, T, Z were used. These are the wall mounted charts that we see in all doctors offices, school nurse stations and and health clinics across America.