Image from page 45 of “Refraction and motility of the eye, with chapters on color blindness and the field of vision” (1920)

$Image from page 45 of "Refraction and motility of the eye, with chapters on color blindness and the field of vision" (1920)$

Title: Image from page 45 of “Refraction and motility of the eye, with chapters on color blindness and the field of vision” (1920)