The Cure of Imperfect Sight by Treatment
Without Glasses - online book

The Original Bates Method, for correcting vision defects

	How the Focus Was Changed           55
	Fig. 24.-Arrangements for Photographing Images Reflected From the Eyeball
	CM, concave mirror in which the subject may observe the images reflected from various parts of her eye; C, condenser; D, diaphragm; L, 1000-watt lamp; F, forehead rest; MP, bar which the subject grasps with her teeth for the purpose of holding her head steady; P, plane mirror upon which is pasted a letter of diamond type and in which is reflected a Snellen test card twenty feet behind the subject (the mirror is just above the letter P); CAM, camera; Pr, perimeter used to measure the angle of the light to the eye; R, plane mirror reflecting light from the 1000-watt lamp upon the eye, which otherwise would be in total dark ness except for the part from which the highly condensed image of the filament is reflected; B, blue glass screen used to modify the light reflected from the mirror R. When the subject read the bottom line of the Snellen test card reflected in the mirror P, her eye was at rest, and when she saw the letter of diamond type distinctly it was accommodated ten diopters, as demonstrated by the retinoscope.