Visual evoked potentials (VEP) are transient brain potentials generated in the visual cortex during visual stimulation. Brain Computer Interface (BCI) using VEP have been investigated for physically handicapped people who have difficulty inputting data with their hands and feet. Our research group has shown that VEP can be discriminated in a short period of time (2s) using the synchronous addition method with visual stimuli of 3.5 Hz or higher. We have also proposed a bandpass filter-based method (BF analysis) as an alternative to synchronous addition, allowing for the investigation of time-series VEP changes. This study measured VEP before and after gazing at a blinking stimulus, investigating VEP changes using BF analysis. Additionally, the characteristics of VEP when moving the gaze up, down, left, and right before and after the blinking were examined using BF analysis. Results showed a delay of several hundred milliseconds before the phase aligns from the start of gazing at the blinking stimulus and a similar delay after blinking stops until the phase becomes unaligned. Displaying the same frequency blinking in the peripheral visual field before and after the blinking made it easier for phases to align. These findings suggest that considering these delays may improve the accuracy of option discrimination.