To investigate the influence of smartphone reading on the ocular surface and to compare the various effects of different screens and light conditions on the ocular surface. 119 volunteers were randomly divided into: Light+Organic Light-Emitting Diode (OLED), Light+electronic ink (eINK), Dark+OLED and Dark+eINK. Ocular surface examinations, including noninvasive break-up time (NIBUT), noninvasive keratograph tear meniscus height (NIKTMH), ocular redness, fluorescein break-up time (FBUT), corneal fluorescein staining (CFS), meibomian gland (MG) assessment, Schirmer I Test and blinking frequency, were performed before and after a reading task. Symptoms were evaluated using the Ocular Surface Disease Index (OSDI) and Computer Vision Syndrome Questionnaire (CVS-Q). NIBUT and FBUT were decreased statistically significantly after participants read on an OLED screen for 2 hours compared with the baseline in light and dark environments, while no statistically significant decrease was observed on an eINK screen. NIKTMH was statistically significantly decreased after reading on an OLED screen in light and dark settings, and the eINK screen had a lesser effect on NIKTMH. An obvious increase in the ocular redness, OSDI and CVS-Q scores was observed after reading on an OLED screen, while the eINK screen had a lesser effect on these indicators. Blink rate increased gradually in OLED subgroups during the reading task, while no statistically significant difference was observed in eINK subgroups. Our research suggested that reading on an OLED screen can cause ocular surface disorder and obvious subjective discomfort, while reading on an eINK screen can minimize ocular surface disorder in both dark and light environments.This article is protected by copyright. All rights reserved.