AIM:To investigate the factor of low visual acuity after phacoemulsification on senile cataract.METHODS:Forty-eight patients 54 eyes with senile cataract were collected,which presented low visual acuity after phacoemulsification and IOL implantation.Medical history,and medical examination of patients before and after operation were collected and the factor of low visual acuity were analyzed.RESULTS:In 48 cases 54 eyes,the best postoperative corrected visual acuities were <0.3,among which optic never injury in glaucoma were 5 eyes(9%),corneal leu-coma and macula were 5 eyes(9%),corneal edema decompensation was 1 eye(2%),high myopia and amblyopia were 11 eyes(20%),senile macular degener-ation were 10 eyes(18%),macular membrane and hole were 9 eyes(17%),diabetic retinopathy were 9 eyes(17%),branch retinal vein occlusion were 2 eyes(4%),reattached retina of retinal detachment was 1 eyes(2%),retinitis pigmentosa was 1 eye(2%).CONCLUSION:The pathological change of fundus is an important reason for the low visual acuity after phacoemulsification.To patients with high danger of low visual acuity,inspect strictly and comply with rules before operation can lower the rate of the low visual acuity after phacoemulsification and reduce medical dispute.