Is it normal to have flickering vision at the side vision (both eyes) for a few minutes everytime in the morning.?

Yes: seeing brief flashes of light in the peripheral vision is very common. but check your vision for new floaters (dark shadowy spots). If you have new floaters, changes in the clarity of your vision or decreased peripheral vision, have your eyes examined by an ophthalmologist because occasionally these flashes may indicate the onset of problems to the retina in the back of your eyes