Page 27 - Practical-Refraction-English

Subjective Refraction 24e which position gives clearer (less blurred) vision and note the location of the negative axis of the cross cylinder, for the patient’s preferred position. Rotate the axis of the correcti- ve cylinder by a small increment towards the axis of the negative cylinder of the cross cylinder. e. Repeat step d until the patient has no preference © Essilor International corrective cylinder is now aligned along the cylinder axis of or almost no preference between positions 1 and 2. The the patient’s refraction. 24i 24f © Essilor International 24j © Essilor International 24g © Essilor International 24k © Essilor International 24h © Essilor International © Essilor International 24l e, f, g, h: Determining the cylinder axis using the cross cylinder alone Alternative technique: c. Place a -0.50D corrective cylinder in the trial frame or phoropter, at an axis located in the middle of the © Essilor International 45° sector identified. d. Position the handle of the cross cylinder along the axis of this cylinder (this is position 1); twist the cross cylinder to present position 2; ask the patient to indicate i, j, k, l : Determining the cylinder axis using a trial cylinder and the cross cylinder 27 Copyright © 2008 ESSILOR ACADEMY EUROPE, 13 rue Moreau, 75012 Paris, France - All rights reserved – Do not copy or distribute.