# Sloan letter

> English word · Noun

## Definitions
1. Any of a set of standard optotypes resembling the letters C, D, H, K, N, O, R, S, V and Z.

## Etymology
They were designed by Louise Sloan in 1959.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/sloan-letter