To investigate effects of refractory errors and anisometropia on final stereopsis in patients with strabismus ,beside the effect of degree and type of deviation.

This was a retrospective study on 259 patients, more than 7 years old, with any type of strabismus who had history of surgical or non-surgical intervention and followed up completely. Stereo acuity was measured using Titmus Stereo Fly test

From 259 patients 164 (63%) were male and 95(37%) female with mean age of 10.4±8.9 years. According to LoGMar scale mean of visual acuity in poor and null stereopsis was 0 .33 but in patients with fine stereopsis was 0.11which was significantly different (p=0.001). Rate of hyperopia,myopia and plano were 78%, 20% and 2% respectively,Hyperopia was more common in null stereopsis(p=0.002). High astigmatism (>1.50) was existed in 34% of all patients .High astigmatism were 36(40%) and 15(16.7%) in null and fine strereopsis respectively which was significantly more seen in null than fine stereopsis(p=0.02).Fourteen present ( 37) of the patients had anisometropia.The rate of anisometropia in null and fine stereopsis group were 48% and 8% respectively that was more common significantly in patients with null and poor than fine stereopsis .

Beside the effects of degree and type of deviation, refractory error and anisometropia are risk facrots for achieving of stereopsis and correction of these factors should be mentioned in planning of the management of strabismus.