A long-term follow-up study was conducted to report power vector analysis of refractive astigmatic changes in a large group of 137 patients (250 eyes) undergoing horizontal strabismus surgery. Fifty-four percent were male. The average age was 9.22±8.21 years. Fifty-five percent had alternating esotropia, 25% had alternating exotropia, 13% had monocular esotropia and 6% monocular exotropia. Average angle of deviation was 37.92±8.97PD. A total of 58.4% had bimedial rectus recessions, 28.8% bilateral lateral rectus recessions and 19% unilateral resection / recession. Horizontal surgery induced a transient significant change in the SE of refraction with a non-clinically significant myopic shift. The study did not find astigmatic changes.