Objective To explore the effects of low-dose CT scan on diagnostic quality of images and the radiation dose to the lens.Methods 60 cases were scanned in axial orientation at different mA.Lens radiation dose was measured and image quality was evaluated.Results Image quality score of group A was(11.2 ± 0.7)points,higher than the group C(4.9 ± 1.8)points(t =12.634,P ＜0.05),and score difference of group B(10.6 ± 1.1)was significantly different(P ＞ 0.05).CTDIvol of group A,group B and group C were 18.32mGy,7.63mGy and 4.58mGy,group B,group C and group A difference was statistically significant(t =15.625 and 14.037,P ＜ 0.05).Group B and C groups difference was not statistically significant(P ＞ 0.05).Conclusion Low dose CT scanning(50mA)in orbit not only could assure the image quality,but also decrease the radiation dose.