Neuromorphic visual systems can emulate biological retinal systems to perceive visual information under different levels of illumination, making them considerable potential for future intelligent vehicles and vision automation. However, the complex circuits and high operating voltages of conventional artificial vision systems present great challenges for device integration and power consumption. Here, we report bioinspired synaptic transistors based on organic single crystal phototransistors, which exhibit excitation and inhibition synaptic plasticity with time-varying. By manipulating the charge dynamics of the trapping centers of organic crystal-electret vertical stacks, organic transistors can operate below 1V with record high on/off ratios close to 108 and sharp switching with a subthreshold swing of 59.8mV dec-1. Moreover, the approach offers visual adaptation with highly localized modulation and over 98.2% recognition accuracyunder different illumination levels. These bioinspired visual adaptation transistors offer great potential for simplifying the circuitry of artificial vision systems and will contribute to the development of machine vision applications. This article is protected by copyright. All rights reserved.