To determine the effect of cyclopentolate, tropicamide, and artificial tear drops on higher order aberrations in normal eyes with OPD-Scan III (Nidek Inc., Tokyo, Japan).

In this study, 189 eyes of individuals aged 20-35 years were selected as samples. Inclusion criteria were a corrected visual acuity of 20/20 or better, a minimum size of about 5mm for the pupil in the dark, hyperopia and myopia less than 5D, and astigmatism less than 2D. Moreover, participants with pathological eye problems, a history of intraocular surgery, and ocular diseases affecting the accommodation, pupil size, and corneal surface were excluded. Higher Order Aberrations (HOAs) of the participants were assessed by the OPD-Scan III before and after cyclopentolate (Colircuss), tropicamide (Mydrax TM 0.5%), and artificial tears (Tearlose) drop instillation

After instilling cyclopentolate drops, the mean of the total RMS increased from 4.580 D to 6.335D, total spherical aberration increased from 0.155D to 0.381D, and total coma increased from 0.195D to 0.369D; the increases were significant for total RMS and total spherical aberration, but a significant relationship was not seen with total coma. After tropicamide, the mean aberrations of total RMS increased from 4.301D to 4.568D, total spherical aberration increased from 0.146D to 0.160D, and total coma increased from 0.213D to 0.230D; the increase was only significant for total coma. On the other hand, after artificial tears, the average of all aberrations decreased in a non-significant manner

Most changes of mean aberrations were related to cyclopentolate drops. Tropicamide and artificial tears had the second and third rank according to their effect on mean errors. As a result, it seems that ocular accommodation is the most important impact on HOA than pupil size. However the pupil size is the second factor for HOAs