Accommodative and pupillary responses for a central target and peripheral stimuli

Objective: To investigate the additive influence of peripheral stimuli, we examined accommodative and pupillary response for a fixation target with peripheral stimuli of different luminance at various distances. Methods: The refractive error and size of pupil diameter were measured monocularly by an autorefkeratometer, looking at a central target of 1 degree of arc at a distance of 100 cm through a hole of 5 degrees of arc on three different test boards of black, white, and random dot texture consisted from black and white at a distance of 33 cm. Results: No statistically significant difference was found among the three groups of three test boads in regard to accommodation. There was a significant value of pupil diameter between black and white test boards (P < 0.05), but no significant differences among others. There was individual variability in accommodative and pupillary responses for peripheral stimulus of random dot texture. Conclusion: When each different peripheral stimulus was given, the pupil diameter grew less in magnitude as the luminance of peripheral surroundings increased, but the accommodative response varied with individuals. It is necessary to consider both refractive and pupillary changes to access the individual accommodative responses of additive influence of peripheral stimuli.