A vision training device, comprising: a housing having at least one eyepiece unit configured to be viewed by an eye of a user; a display configured to display a target image in front of a fixation axis of the user; a lens disposed between the eyepiece unit and the display unit; an actuator configured to move at least one of the display and the lens along the fixation axis; a control unit configured to set a training range within a movable range (MR) of the display and the lens and to control the actuator such that at least one of the display and the lens is moved within the training range; and at least one of a user input unit , a sensor module, or combinations thereof; wherein the control unit is configured to: (a) set an accommodation range (AR) corresponding to a range between a near point of accommodation position (P5) and a far point of accommodation position (P6) within the movable range (MR), and (b) set the near point of accommodation position and the far point of accommodation position based on at least one of accommodation reflex confirmation signals from the user input unit , accommodation state change confirmation signals from the sensor module, or combinations thereof; wherein (a) the training range includes the accommodation range, (b) the accommodation state change confirmation signals correspond to the eye of the user transitioning from the accommodated state to the non-accommodated state or from the non-accommodated state to the accommodated state, and (c) the near point of accommodation position is closer to the eye of the user than the far point of accommodation position. a housing having at least one eyepiece unit configured to be viewed by an eye of a user; a display configured to display a target image in front of a fixation axis of the user; a lens disposed between the eyepiece unit and the display unit; an actuator configured to move at least one of the display and the lens along the fixation axis; a control unit configured to set a training range within a movable range (MR) of the display and the lens and to control the actuator such that at least one of the display and the lens is moved within the training range; and at least one of a user input unit , a sensor module, or combinations thereof; wherein the control unit is configured to: (a) set an accommodation range (AR) corresponding to a range between a near point of accommodation position (P5) and a far point of accommodation position (P6) within the movable range (MR), and (b) set the near point of accommodation position and the far point of accommodation position based on at least one of accommodation reflex confirmation signals from the user input unit , accommodation state change confirmation signals from the sensor module, or combinations thereof; (a) set an accommodation range (AR) corresponding to a range between a near point of accommodation position (P5) and a far point of accommodation position (P6) within the movable range (MR), and (b) set the near point of accommodation position and the far point of accommodation position based on at least one of accommodation reflex confirmation signals from the user input unit , accommodation state change confirmation signals from the sensor module, or combinations thereof; wherein (a) the training range includes the accommodation range, (b) the accommodation state change confirmation signals correspond to the eye of the user transitioning from the accommodated state to the non-accommodated state or from the non-accommodated state to the accommodated state, and (c) the near point of accommodation position is closer to the eye of the user than the far point of accommodation position. <EOS>