PurposeTo compare objective accommodation of phakic and pseudophakic eyes between two different age groups.MethodsEighty-three eyes (83 participants aged 40years) with a visual acuity of 20/25 or better, and refractive error < spherical -1.0diopters (D) and cylindrical 1.0D, were included. Forty-four patients had undergone phacoemulsification and monofocal intraocular lens implantation and were examined 6months post-surgery. Participants were divided into groups 1 (pseudophakic, age <60years), 2 (pseudophakic, 60years), 3 (phakic, <60years), and 4 (phakic, 60years). Objective accommodation and pupil diameter to 2.0- and 3.0-D stimuli were measured with a binocular open-field autorefractor.ResultsThe mean objective accommodation was 0.290.47D, 0.01 +/- 0.21D, 1.00 +/- 0.88D, and 0.01 +/- 0.13 to a 2.0-D stimulus, and 0.26 +/- 0.51D, -0.06 +/- 0.21D, 1.42 +/- 1.21D, and -0.06 +/- 0.21 to a 3.0-D stimulus in groups 1, 2, 3, and 4, respectively. For both stimuli, the values in group 1 exceeded those in groups 2 and 4, and were smaller than those in group 3, while the values in group 3 exceeded those in groups 2 and 4. The mean pupillary diameter was -0.5 +/- 0.8mm, -0.3 +/- 0.8mm, -0.6 +/- 0.5mm, and -0.6 +/- 0.9mm to a 2.0-D stimulus, and -0.6 +/- 0.8mm, -0.6 +/- 0.8mm, -0.9 +/- 0.5mm, and -1.0 +/- 1.1mm to a 3.0-D stimulus in groups 1, 2, 3, and 4, respectively. There was significant correlation between objective accommodation and changes of pupil size for both stimuli.Conclusion Age seems to play a role in objective accommodation among relatively young pseudophakic patients.