Save your left_eye image as 3d_image, as this will be your final image.Select your 3d_image, and display the channel window. If it is not visible, activate it by going to WindowChannels.Select only the BLUE and GREEN channels by clicking one of them, and then selecting the other by pressing SHIFT as you click. Your image should now be only in blue.Next select your entire right_eye image by going to SelectAll. Copy it and paste it into the 3d_image, with only the blue and green channels still selected.Now click the eye next to the RGB Channel, to activate all channels. Your image will now have a blue and red image overlapping.Technically, you are done now, but your image might need some adjusting