AIM:To analyze the relationship between asthenopia and range of fusion after laser in situ keratomileusis(LASIK) in myopia patients,and to provide another evidence for the diagnosis of visual fatigue,and expect to provide new ideas for the treatment of asthenopia.·METHODS:Totally 60 myopia cases (120 eyes),whose diopter was from-1.50D to-8.00D,were determined the ratio of fusion range and AC/A by synoptophore and refracted by autorefractor and phoropter.Myd rin was used to disperse pupil then,refraction was performed again by autorefractor and phoropter before LASIK,1 week and 1 month after LASIK and visual fatigue questionnaire survey was conducted.The results were statistically analyzed.·RESULTS:There were 54 cases of postoperative occurr-ed visual fatigue symptoms in 60 patients.The discre-pancy of spherical equivalecce(SE) was significant different between large pupil and normal pupil 1 week,1 month after operation (P<0.01),all SE diminished.The discrepancy of SE 1 week,1 month after operation was significantly larger than that before operation (P<0.05).The fusion range 1 week,1 month after operation were lower than the preoperative one respectively,the result had significant difference (P<0.05).The radio of AC/A 1 week after operation was larger than the preoperative one,and the radio of AC/A 1 month after operation was lower than the preoperative one,the result had significant difference (P<0.05).·CONCLUSION:The accommodation of the myopia eyes increases and the convergence diminishes after LASIK.The imbalance of accommodation and convergence is an important factor in fatigue of patients after LASIK.This requires that we should take into account patient’s accommodation and convergence when we design surgery.