To analyze the ocular wavefront aberrations in patients with facial dystonia treated with botulinum toxin A. Patients with benign essential blepharospasm and hemifacial spasm in activity underwent slit lamp examination and bilateral wavefront analysis under pharmacologic mydriasis using Alcon LADARvision wavefront aberrometry system. After that, all patients were treated with botulinum toxin A injections performed by the same ophthalmologist. After one month, the wavefront analysis was performed in the same way and by the same examiner. The main outcome measure was the change in ocular wavefront aberrations. Paired T-test was used to compare pre and post-injection numeric wavefront values. From a total of 11 patients enrolled in this study, 6 (54.5%) had essential blepharospasm and 5 (45.5%) had hemifacial spasm. The fellow eyes of patients with hemifacial spasm were not included, totalizing 17 eyes with spasm. Eight patients were female (72.7%) and three were male (27.3%), the male:female ratio was 1:2.6. The age ranged from 50 to 72 years old with a mean of 65.9 ± 8.2 years. The mean of high order root mean square (RMS) wavefront aberrations was 0.68 before and 0.63 one month after the treatment (p=0.01). Before the treatment, the mean of spherical aberration was 0.23 and decreased to 0.17 one month after the treatment (p=0.01). There was no significant difference in the other higher-order aberrations before and after the treatment (p>0.05). The treatment with botulium toxin may decrease spherical aberrations in patients with facial dystonia.