An image generation system comprising an image rendering unit operable to render a first image for display to a first one of a user's eyes, an image obtaining unit operable to obtain a second image for a second one of the user's eyes, the obtained image having been rendered for display at an earlier time, an image reprojection unit operable to reproject the first image from a viewpoint associated with the first one of the user's eyes to a viewpoint associated with the second one of the user's eyes, and an image generation unit operable to generate an output image for the second one of the user's eyes in dependence upon the reprojected first image and the obtained second image.