We evaluate the effect of the emmetropization technique LASIK (laser-assisted in situ keratomileusis) on stereoscopic vision. For this, we used a mirror stereoscope to measure the upper disparity limit D(max) before (with best correction) and after LASIK for 30 patients. The results show that the upper disparity limit declines from 41.1 min of arc on average to 31.3 min of arc after LASIK, being significant in 83% of the patients. This deterioration is significantly correlated with an increase in the postsurgical interocular differences in higher-order aberrations, corneal asphericity, and presurgical anisometropia. New ablation algorithms should minimize interocular differences in order to improve binocular visual performance.