entrance pupil
4.Methods Eyesys Corneal Analysis System was used for the computer assisted analysis of corneal differential topographical maps gained preoperatively and 10 days postoperatively in 158 eyes of 98 patients with at least six months of follow up to determine the direction and the distance of the center of ablation zone relative to the center of the entrance pupil,and a comparison in decentration difference was made between one zone ablated eyes and multi zone ablated eyes.

