Vision Improvement in Keratoconus Patients Trained With Perceptual Learning: A Randomized Controlled Trial.

Purpose: To investigate the effectiveness and maintenance of perceptional learning (PL) on vision improvement in keratoconus (KC) patients corrected with spectacles.

Design: Randomized, double-blind clinical trial.

Methods: Non-progressive KC patients 9 years of age or older who had best spectacle-corrected distance visual acuity (CDVA) of 0 to 1.