Change Amplitude of Accommodation and Lens Adaptation after Adding Spherical Lens

Abstract

Purpose: To evaluate the lens adaptation by comparing the changes of amplitude of accommodation against adding power of (±) spherical lenses. Methods: 51 subjects (26 men and 25 women) aged 21.76±1.76 years participated for this study. Refractive errors of subjects were fully corrected, S+1.00 D, S+2.00 D, S+3.00 D, S-1.00 D, S-2.00 D, and S-3.00 D were added in the order on each eye, and after that, monocular amplitude of accommodation (AA) was measured using a push-up method at 0, 15, and 30 minutes for each subject. The values were statistically compared to those of fully corrected state and the change level of AA between before and after adding lens was calculated as a relative ratio to the each spherical diopters added. Results: After S+1.00 D, S+2.00 D, or S+3.00 D was added, the AA was significantly (p<0.001) higher than that of fully corrected state. However, the change level of the AA was by 55~68% of the adding spherical diopter. After S-1.00 D, S-2.00 D, or S-3.00 D was added, the AA was significantly (p<0.001) lower than that of fully corrected state. The change level of the AA was by 72~105% of the adding spherical diopter. Conclusions: When prescribing a spherical lens related to accommodative functions, clinical practitioners have to consider that the change of AA is mostly smaller than the power of added spherical lens because of lens adaptation.