Purpose To investigate the effects of reading with mobile phone versus text on accommodation accuracy and near work-induced transient myopia (NITM) and its subsequent decay during near reading in young adults with mild to moderate myopia. Methods The refractions of 31 young adults were measured with an open-field autorefractor (WAM-5500, Grand Seiko) for two reading tasks with a mobile phone and text at 33 cm. The mean age of the young adults was 24.35 +/- 1.80 years. The baseline refractive aspects were determined clinically with full distance refractive correction in place. The initial NITM and its decay time and accommodative lag were assessed objectively immediately after binocularly viewing a mobile phone or text for 40 min. Results The mean +/- standard deviation (SD) initial NITM magnitude was greater for reading with text (0.23 +/- 0.26 D) than for reading with mobile phone (0.12 +/- 0.17 D), but there was no significant difference between the two reading tasks (p = 0.082). The decay time (median, first quartile, and third quartile) was 60 s (16, 154) and 70 s (32, 180) in the phone task and text task groups, respectively. There was also no significant difference in the decay time between the two reading types in general (p = 0.294). The accommodative lags of text tasks and mobile phones tasks were equivalent (1.27 +/- 0.52 D vs 1.31 +/- 0.64 D, p = 0.792). Conclusion There were no significant differences in accommodative lags and the initial NITM and its decay time between reading with a mobile phone and text in young adults.